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Neuro

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4 Lesions that will cause coma or loss of consciousness:
1. Upper brain stem
2. Midbrain and hypothalamus
3. Diencephalon
4. Bilateral lesions of cerebral cortex
Loss of consciousness in 1. _____ is brief in duration and sudden in onset;
More prolonged and profound loss of consciousness is described as 2. _____
3. Lesser grades of depressed consciousness characterized by variable degrees of impaired reactivity.
1. Syncope (fainting)
2. coma
3. Stupor or obtundation
5 Intracranial causes of coma:
1. head injuries
2. cerebrovascular accidents
3. CNS infections
4. Tumors
5. increased intracranial pressure
4 Extracranial causes of coma:
1. Vascular disorders (shock/hypotension caused by severe hemorrhage or myocardial infarction)
2. metabolic disorders (diabetic acidosis, hypoglycemia, uremia, hepatic coma, addisonian crisis, electrolyte imbalance)
3. intoxication (with alcohol, barbiturates, narcotics, bromides, analgesics, carbon monoxide, heavy metals)
4. miscellaneous disorders (hyperthermia, hypothermia, severe systemic infections)
Glasgow Coma Scale offers a practical bedside method of assessing level of consciousness based on 3:
eye opening and verbal and motor responses
1. Main center for bringing on sleep
2. through the release of
3. REM sleep occurs due to the release of?
4. from?
1. Midline raphe system of the pons
2. serotonin
3. NE
4. Locus ceruleus
Multiple types of sensory input including _____ can activate the reticular formation and produce a generalized increase in cerebral cortical activity or arousal.
somatosensory, auditory, visual, visceral
Activity within the _____ and _____ are both required for maintaining consciousness.
cerebral cortex and mesencephalic reticular activating system
4 Nuclear groups comprising the reticular formation include:
1. Median raphe
2. Paramedian reticular
3. Medial reticular
4. Lateral reticular
Median raphe nuclei:
The median raphe nuclear group includes the following midline nuclei: raphe obscurus and raphe pallidus in the medulla oblongata; raphe magnus in the caudal pons and rostral medulla; raphe pontis in the pons; and the dorsal raphe and superior central (Bekhterev) nuclei in the midbrain. The neurotransmitter of most raphe nuclei is serotonin.
Paramedian reticular nuclei:
The paramedian reticular nuclei are located lateral to the medial longitudinal fasciculus and the medial lemniscus. They include the paramedian reticular nucleus in the rostral medulla and caudal pons, and the reticulotegmental nucleus in the rostral pons and caudal midbrain.
Medial reticular nuclei:
The medial reticular nuclear group includes the nucleus reticularis gigantocellularis in the medulla oblongata, and the nucleus reticularis pontis caudalis and nucleus reticularis pontis oralis in the pons.
Lateral reticular nuclei:
The lateral reticular nuclear group includes the following nuclei: nucleus reticularis parvocellularis and nucleus reticularis lateralis in the medulla oblongata; the nucleus reticularis parvocellularis in the pons; parabrachial and pedunculopontine nuclei in the rostral pons and caudal midbrain; and the cuneiform and subcuneiform reticular nuclei in the midbrain.
The reticular nucleus of thalamus, located lateral to the _____, is a continuation of the brain stem reticular formation.
Internal capsule
3 Cholinergic system nuclei:
1. pedunculopontine reticular nucleus
2. lateral dorsal tegmental nucleus
3. nucleus basalis of Meynert
The _____, located in the basal forebrain, sends axons to almost the entire cerebral cortex. Degeneration of cholinergic neurons in this area is associated with memory decline in Alzheimer's disease.
nucleus basalis of Meynert
Four types of monoamine neurons have been identified within the brain stem reticular core:
1. dopaminergic
2. noradrenergic
3. adrenergic
4. serotonergic
3 dopaminergic pathways:
(1) mesostriatal (nigrostriatal), from the substantia nigra to the striatum (caudate and putamen). Interruption of this system is associated with Parkinson's disease.
(2) mesolimbic, from the ventral tegmental area to limbic nuclei. Overactivity of this system is associated with schizophrenic hallucinations.
(3) mesocortical, from the ventral tegmental area to the prefrontal cortex. Lesions in this system are associated with cognitive deficits in Parkinson's disease.
2 noradrenergic components:
1. locus ceruleus
2. lateral tegmental norepinephrine system
Adrenergic system
Adrenergic neurons are located in the same regions of the caudal medulla as the noradrenergic neurons. They project to the spinal cord, brain stem, thalamus, and hypothalamus. This system is small in comparison with the dopaminergic and nor-adrenergic systems and represents a minor component of the monoaminergic system.
Serotonergic system
Serotonergic neurons comprise nine cell groups designated B1 to B9.
The 1. _____ system neurons have a discrete topography and restricted area of terminal distribution, whereas the 2. _____ neuron systems have a more diffuse and wide-spread projection.
1. dopaminergic
2. noradrenergic, adrenergic, and serotonergic
Increase in life expectancy due to advances in: (3)
1. housing/sanitation
2. public health (antibiotics, vaccination, reduced infant mortality account for most of changes)
3. biomedical science (mostly decreased heart disease and stroke)
-Normal aging of the nervous system is non-uniform among individuals
-Aging of the nervous system involves both 2. _____ and _____
-Aging processes diminish efficiency of nervous system function and increase vulnerability, independently of neurodegenerative disease
-Significant components of nervous system aging can be reversed or delayed
1. non-uniform
2. Functional decline and adaptive responses
Normal aging: 4 Histologic changes:
-High degree of individual variation
1. SMALL, region-selective decrease in neuron number
2. Decrease in dendritic extent, spine density
- Increased in early senescence and reduced in later life
- Decreased in cerebellar Purkinje neurons
3. Modest decrease in synapses
4. Increases in Alzheimer's disease-associated pathological changes in small amounts
Normal aging-related cell loss was overestimated:
-Morrison & Hof and others suggest that previous data is contradicted when 1. _____ techniques are used (Beginning 1993-1994).
-Older methods did not allow estimation of volume of the structure containing the neurons being counted.
-Density estimates were thus confounded with age- or procedure-related changes in structural volume.
-Only estimates of 2. _____ within a structure can be used to evaluate neuronal loss.
-Implication is that all old data are suspect.
1. unbiased stereological (US)
2. total cell number
Neuronal loss in normal aging:
Where does cell loss take place?
1. Subiculum of Hippocampus
2. Nigrostriatal monoamine
3. Cerebellum (granule and purkinje cells)
Purkinje neuron vulnerability:
-Purkinje neuron density is associated with competency of 1. _____ and _____
-Also linked to 2. _____ learning (classical conditioning).
-3 Reasons for selective vulnerability:
1. balance and coordination
2. associative learning (classical conditioning)
3. High firing rate during waking and sleep
Continuous metabolic activity
High synaptic plasticity
*****Normal aging: 5 Gross changes:
1. 15% loss of mass
2. Cortical gyri decrease in size, sulci are wider
3. Enlargement of ventricles
4. Some arterial disease affecting large and small vessels is common
5. Not necessarily indicative of psychomotor or cognitive dysfunction
Normal aging: Dendritic extent:
Hippocampus:
-1. _____ and _____- dendritic length 2. _____ from middle (40-60) to old (68-79) followed by regression to middle age level in very old (86-95).
-CA2-3, CA1, Subiculum - complete stability across ages for normals.
1. Parahippocampal gyrus and dentate gyrus
2. increases
Normal aging: 7 Biochemical/Physiologic changes:
1. Reduced protein content
2. Increased DNA (due to gliosis)
3. Increased oxidative molecular damage - increased iron content (transitional metals)
4. Minimal decrease in lipid & water content
5. Reduced blood flow and oxygen consumption
6. Functional changes (e.g., ↓evoked potentials; ↓ long-term potentiation)
7. Loss of synapses
Normal aging: 5 Neurotransmitter changes:
1. Decreased Glut, NE, DA, ACh, 5-HT
2. Reduced biosynthesis
3. Impaired release
4. Little change in receptor number or sensitivity
5. Reduced sensitivity in postreceptor signal transduction pathways (ubiquitous, not selective)
Normal aging: Functional changes:
-High degree of individual difference
-Mild to moderate decline: (5)
-Deficits tend to be partially or fully alleviated by practice and reduction of time requirements.
1. Recent memory (rapid forgetting)
2. Executive function
3. Visuospatial function
4. Reaction time performance
5. Sensorimotor skills (e.g., driving)
Effects of aging on memory:
Primary memory (STM) (consider properties of performance, capacity, decay)?
-Age differences magnified by increasing attention requirements (i.e., dialing phone number versus verbal recall)
-Decay more rapid in old vs young ("rapid forgetting")
-"very impaired" in AD; not distinguishable from aging in early AD
Small decrease in digit span (10%)
Effects of aging on memory:
-If original learning is equated (increase time for older persons), deficits can be alleviated.
-Cued recall/recognition studies: PET imaging studies suggest that when performance of young and old are equated, old subjects have low activity in areas that are high in young, but show increases in other areas.
-Suggests _____ by engaging different memory systems. (e.g., right prefrontal cortex in young, both right and left in old)
Adaptive compensation
Effects of aging on Implicit and explicit memory:
**-"Priming" (cued recall) 1. _____ affected by age than free recall
-Serial position: primacy more affected than recency
-motor skill acquisition rate in some cases improved (but performance may be impaired because of psychomotor dysfunction) (e.g., older typists are slower and make more errors)
**-classical conditioning - slower learning, reduced magnitude of 2. _____
1. less
2. conditioned response (CR)
Effects of aging on memory:
Semantic memory:
-Confrontation naming (e.g., name these objects)
-Semantic fluency (name animals; name words starting in S)
1. Consistent age related deficit. Interpreted as reflection of "cognitive slowing" based on lack of age-related increase in "errors" and amelioration by conversion to a recognition task.
2. Contrast with clear deficits in AD
Effects of aging on other cognitive functions:
Language:
****-Vocabulary 1. _____
-Declines in 2:
-Word recognition 3. _____ in normal aging; impaired in AD.
1. intact or improved
2. spontaneous language production, sentence length
3. intact
Effects of aging on visuospatial function:
-Ability to perceive and manipulate visual information.
-Tests: reproduce figures or recognize similarity
- Form perception (object recognition): inferior temporal and occipital regions ("what" system)
- Spatial judgement (movement & spatial relationships) right occipitoparietal junction ("where" system).
- Moderate but robust decline with age; very predictive of overall cognitive decline
- Very impaired in AD (important clinical diagnostic)
-Clock-drawing test: (used as fast screening for AD)
Normal aging vs Alzheimer's Disease:
-AD involves progressive loss of memory and _____
-Often includes: Aphasia, apraxia, agnosia, visuospatial impairment, loss of executive function
-Early stages of AD difficult to differentiate from normal aging
-Only small percentage eventually show AD
at least one other cognitive domain (learning, reasoning, problem solving, abstract thinking)
Praxis
Something you are ordered to do
Dementia: definition
- Loss of intellectual functions (memory, learning, reasoning, problem solving, abstract thinking)
-Must be 1. _____ losses for diagnosis
-Involuntary functions 2. _____ (although lost in more advanced stages)
-Over 50 disorders known to cause dementia
1. multiple
2. intact
Dementia: Classifications
1. _____ Syndromes (hyperthyroidism, Cushings disease, nutritional deficiencies, AIDS dementia, etc.)
2. _____ Syndromes (Huntington's chorea, Parkinson's disease, Schilder's disease, Creutzfeldt-Jakob disease; brain tumors, brain trauma, meningeal infections
3. _____ (Alzheimer's disease, Vascular dementia)
1. Medical syndromes
2. Neurologic syndromes
3. Dementia
AD: 4 Functional deficits
1. Memory (especially new LTM) (declarative mem.) (i.e., H.M. - like memory deficit but not as selective)
2. Language (word finding, empty speech, circumloculation)
3. Visuospatial (figure reproduction, geographic disorientation)
4. Personality & affect (variable manifestation, depression, paranoia, etc.)
AD: Gross pathology
-Mostly nonspecific, similar to normal aging but more pronounced.
-Cortical atrophy (pronounced in early onset)
-gyral atrophy, widening of sulci
-all regions except 1. _____
-Limbic atrophy (pronounced in late onset)
-Ventriculomegaly
Gross features specific to AD are 2. _____
1. occipital lobes
2. atrophy of olfactory bulb & tracts; hippocampus
Which aphasias involved word finding difficulty?
Transcortical and Wernicke's aphasias
Visuospatial degeneration in AD affects what parts of the brain?
Visual association cortex:
occipitotemporal "what" cortex
occipitoparietal "where" cortex
Personality and affect changes in AD affect what part of brain?
Limbic system
AD: 5 Histologic changes
1. ****neuronal loss (not present in normal aging)
2. neurofibrillary tangles (NFT)
3. neuritic plaques (SP) w/ BetaAP (ABeta)
4. synaptic loss (due to axonal/dendritic loss)
5. cerebral amyloid angiopathy (CAA) accumulation of amyloid beta (ABeta) in small to mid-sized vessels of meningeal and superficial cortical vessels
Neuronal loss: Association Cortex
-Loss of corticocortical projection neurons in association areas of neocortex
-In neocortex, AD-associated neuronal loss involves 1. _____ and 2. _____
-Loss is relatively selective for 3. _____
1. inferior temporal cortex (ITC)
2. superior frontal cortex (SFC)
3. corticocortical projection
What kind of NT is lost in AD?
Glutamate
Histology of neocortical cell loss in AD:
-Midsize and small 1. _____ cells; _____neurons; associate with AD pathology and decrease in density
-Axons of 2. _____ corticocortical pyramidal cells most vulnerable:
3. 3 Affected layers?
-Global disruption of long neocortical connections.
-Diffuse cortical 4. _____ lost in all layers
-Primary cortices spared; Large layer V pyramidal cells forming brainstem and cord projections 5. _____
1. pyramidal cells; stellate neurons
2. glutamatergic
3. II (external granular layer)
III (external pyramidal layer)
V (internal pyramidal layer)
4. afferents (NE; ACh)
5. not vulnerable
Hippocampal/cortical circuitry in AD:
1. What is affected?
2. Early cell loss in EC and Subiculum _____ the hippocampus from input and output!
1. Entorhinal cortex, Hippocampus CA1, and Subiculum (all glutamatergic)
(compared with only the subiculum in normal aging)
2. isolate
Hippocampal/cortical circuitry loss in AD:
-Perforant pathway
- Originates in layer II of entorhinal cortex (EC) and terminates in dentate gyrus (DG) of hippocampus.
- Provides key interconnection between neocortex and hippocampus.
- Represents convergence of inputs from association cortex, funneling processed neocortical information into dentate gyrus. Has critical role in memory; synaptic plasticity.
- Input from: 1. _____, _____, and _____
-Hippocampus proper: most severe loss in 2. _____ and _____.
-3. Cell loss in 4:
1. visual, auditory, and taste association cortices
2. subiculum and CA1
3. olfactory bulb, cingulate gyrus, amygdala, and prelimbic cortex
First site of cell loss in AD is?
Entorhinal cortex, followed by cell loss in the hippocampus
3 Subcortical projection pathways (NT)
1. Dorsal bundle (noradrenergic)

Arousal/Wakefulness - Important for memory formation:
2. Basalo-cortical (cholinergic)
3. Septo-hippocampal (cholinergic)
Neuronal loss in aging and AD:
Only areas spared are:
1. Primary cortices
2. Nigrostriatal monoamine
3. Cerebellum
AD: Genesis of NFT
-NFT = paired helical filaments composed of 1. _____ protein
-2. _____ of tau from microtubles leads to destabilization (microtubule dysfunction, loss)
-3. _____ leads to aggregation
-Aggregations form 4. _____
1. hyperphosphorylated tau protein
2. Dissociation
3. Hyperphosphorylation
4. paired helical filaments (PHF)
Genesis of neuritic plaques:
-ABeta = abnormal cleavage of 1. _____, locus on chromosome 21
-APP normal membrane-spanning protein
-normal cleavage to soluble fragments (by Alpha-secretase) (1-40); non-amyloidogenic
-cleavage through membrane-spanning region yields ABeta (2. _____) = BAD
-fibril formation - Beta-pleated sheet
1. amyloid precursor protein (APP)
2. 42/43
AD: Biochemical/Physiologic changes (3)
Similar to normal aging but exacerbated
1. Reduced protein content
2. Increased oxidative molecular damage
3. Reduced blood flow and oxygen consumption
*****AD: Neurotransmitter changes
-4 NTs that show prominent early presynaptic loss
-2 NTs spared until late stages
-Reduced biosynthesis, release, etc. secondary to neuronal loss
1. ACh, NE, somatostatin, glutamate
2. GABA, DA
AD: Genetic factors (familial)
-25% of patients have relative with dementia or AD (sporadic)
-familial AD - multigenerational involvement, large pedigree (early and late onset forms)
-mutation on chromosome 21 affecting APP processing (early FAD)
-genes coding for presenilins (presenilin 1, chromosome 14; presenilin 2, chromosome 1)(Early FAD)
...
AD: Genetic factors (sporadic)
-Apolipoprotein 1. __ gene dose (chromosome 19)
-Many functions, cholesterol transport
-Highest concentrations in liver and brain (macrophages & astrocytes)
-Risk: alleles 2. _____ (increase of 20-90%)
-Possible mechanisms: different effects of alleles on 3. _____ of tau; amyloid fibril formation or protection from toxic effect of ABeta or free radicals.
1. E4
2. E4>E3>E2
3. hyperphosphorylation
AD: Pathogenic hypotheses
-beta amyloid (linked to genetic abnormality)
-tau protein (phosphorylation modulators)
-free radicals (linked to mitochondrial abnormality)
-accelerated aging
-infectious (prion)
-environmental toxicity
...
_____ - loss of ability to make decisions
Abulia
Syndrome?
Abulia- loss of ability to make decisions
Impaired ability to develop new strategies to deal with novel situation
Results in diminished work performance
Still has values, long-term goals and motivation related to work activities
Classic deficits on neuropsychological tests requiring sensory-linked planning
Trail-making test
Wisconsin Card Sort
Slower learning of set
Perseveration with old set when faced with shift in set
Dorsolateral syndrome
1. STM =
2. LTM =
1. Immediate memory = 7-digit recall
2. Remote and recent memory
Syndrome?
Unable to link plans for behavior to motivation and values; impulsive; change in personality
Performance on tests of dorsolateral prefrontal function are average or above
Illustrates orbitofrontal function: internal, limbic-linked (crazy emotions) planning
Orbitofrontal syndrome
Syndrome?
Akinesia
Motor impersistence
Dorsomedial Syndrome
*Illustrates dorsomedial prefrontal cortex function in initiating and sustaining of goal-directed behavior
Dorsomedial prefrontal cortex functions in _____ and _____ goal-directed behavior.
initiating and sustaining
1. Condition?
2. Site of lesion?
Improper execution of automatic behavioral routines (e.g., putting on several pairs of glasses; public urination)
Behavior driven by dorsolateral pfc is intact, but inadequately inhibited by orbitofrontal system
1. Utilization behavior
2. Orbitofrontal
With utilization behavior, behavior driven by dorsolateral prefrontal cortex is intact, but is inadequately inhibited by _____ system.
orbitofrontal
Apraxia
Inability to carry out an activity on command
Arousal (wakefulness/alertness):
1. _____ system in midbrain reticular formation (MRF) 2. 2 nuclei involved?
Lesion causes 3. _____
Stimulation promotes wakefulness; forward motion
MRF modulates cortical activity:
- Direct connections via 4. _____
- Indirectly via 5. _____
NR transmitter is 6. _____
Active during both 7. _____ and in _____
1. Indirect cholinergic (Ach)
2. Pedunculopontine nucleus (lateral group) and Laterodorsal tegmental nucleus
3. somnolence/lethargy
4. midline thalamic nuclei
5. thalamic reticular nucleus (NR) (enabling thalamic throughput)
6. GABA
7. wakefulness and in REM sleep
Arousal (wakefulness/alertness):
1. 3 Direct aminergic arousal systems (direct to cortex) (include associated NT)
2. 2 Non-aminergic arousal systems (NT)
3. Enabling circuit: (NT)
1. Tuberomamillary nucleus (histamine)
Locus ceruleus (norepinephrine)
Raphe nuclei (serotonin)
2. Nucleus basalis (acetylcholine)
Lateral hypothalamic neurons (orexins)
3. Lateral hypothalamic neurons (orexins)
NREM sleep (I-IV):
1. _____ of thalamocortical neurons
Slow wave activity driven by 2. _____
Low sk. muscle activity; slow eye movements
Reduced HR, BP & Resp. (parasympathetic predominance)
Lower core and brain temp; metabolic rate
Reduced cortisol, thyroid; increased GH, testosterone, prolactin, insulin, glucose
1. Hyperpolarization
2. Reticular thalamic nucleus (NR)
Awake - Stage I (claims not sleeping)
Unsynchronized
Drowsy (1. _____)
Stage 1: Synchronized (2. _____)
Stages 2:
Vertex wave/sleep spindle
Stages 3/4:
Slow rhythm (3. _____) (slow wave sleep)
REM
Waking-like EEG; eye movement; loss of muscle tone, ANS activity
1. Alpha
2. Theta
3. Delta
REM sleep:
Waking-like EEG
Hypotonia; especially neck
Increased BP & HR; irregular breathing
Rapid eye movements
1. _____ spikes
2. _____, _____, and _____ achieve high firing rates (active state)
Lower threshold for arousal than from IV
Subject most likely to remember dream when awakened from REM
1. Ponto-geniculo-occipital (PGO) spikes
2. Limbic system, hypothalamus, and brain stem
1. Direct arousal system is active during?
2. Indirect arousal system is active during?
1. ONLY during wakefulness
2. During BOTH wakefulness and REM sleep
Indirect pathway = _____ pathway
Ach pathway
Thin sheet of neurons that envelops thalamus and projects onto thalamic neurons
Reticular thalamic nucleus (NR)
Neurobiology of NREM sleep:
Interaction between sleep-inducing and arousal mechanisms
Onset driven by GABA cells in 1. _____
VLPO inhibits 2. _____ and _____ arousal systems
VLPO and direct (aminergic) arousal systems are mutually 3. _____
VLPO remains active during sleep
Delta waves spindling reflect intrinsic properties of 4. _____ neurons and _____
VLPO regulates onset and maintenance of 5. _____; abolished by lesioning
1. Ventrolateral preoptic nucleus (VLPO)
2. indirect (cholinergic) and direct (aminergic)
3. inhibitory
4. thalamocortical neurons and Reticular thalamic nucleus (NR)
5. Slow-wave sleep (SWS)
In waking up, the indirect arousal system is disinhibited indirectly due to inhibition of Ventral Lateral PreOptic (VLPO) area-mediated inhibition by the _____.
Direct (aminergic) system
Neurobiology of REM sleep:
Regulated by different populations of Ventral Lateral PreOptic (VLPO) neurons
The 1. _____ interacts with direct arousal system in onset and offset of NREM sleep -> _____
2. _____ interacts with subsets of arousal nuclei in initiation of REM: (4)
5. Remains inactive throughout sleep?
Activation of additional descending 5. _____ pathways mediating loss of muscle tone
1. cluster (core) subnucleus -> Tuberomamillary (histamine) nuclei
2. Extended subnucleus
3. Locus ceruleus, Raphe nuclei, Pedunculopontine nuclei, Laterodorsal tegmental nuclei
4. Tuberomamillary (histamine) nuclei
5. Glutamatergic
Circadian control of sleep cycle:
Intrinsic sleep cycle is 25 h
1. _____ entrain rhythms via direct retinal-suprachiasmatic pathway:
- Light
- food availability
- temperature
- social ques
2. _____ nucleus
- lesioning abolishes circadian cycles and REM cycle
1. Zeitgebers
2. Suprachiasmatic nucleus (SCN)
Narcolepsy:
Fall asleep at inappropriate times
1. _____ (weakness during emotional arousal)
Sleep paralysis and hypnopompic hallucinations
Components of REM occurring in wrong context:
- Loss of muscle tone during wakefulness (sleep paralysis or cataplexy)
- Vivid dreams during stage 1 (2. _____) or at the end of sleep (3. _____)
Associated with impaired function of 4. _____
1. Cataplexy
2. hypnogogic
3. hypnopompic
4. orexin
Attention:
Process of focusing on a single source of sensory input
Intentional: conscious, deliberate focusing (1. _____ cortex)
- Required for attention
Reactive: shift in attention due to potent or salient stimulus (bug bite) (2. _____ + area)
- Unconscious
Orienting response: 3. _____ + area and _____
1. Dorsolateral prefrontal cortex - required for attention
2. Parietal polymodal association cortex (area 7) - unconscious
3. Frontal eye fields (area 8) and superior colliculi
Condition?
-Initial severe impairment in intentional and reactive attention and orienting response (no stimulus will induce a left saccade)
-Left hemiakinesia (not hemiparesis because patient can move if arm is brought into right hemispace
-Left hemianopia (not due to damage to ascending visual pathways because normal vision occurs when left retinotopic visual fields are brought into the right hemispatial field
-Left hemibody sensory loss - able to detect stimuli in left hand when it is placed in right hemispace.
Hemispatial neglect - more common in right hemispheric stroke
Association cortex has a key role played by cortico-cortical pyramidal neurons in layers ____ and _____ of cortex
II and III
Location/movement "where" visual pathway (occipitoparietal) (dorsal stream) allows use of information from _____ attributes of objects
motion
Language:
-Localized in polymodal/supramodal cortex in 1. _____ region of 2. _____ hemisphere
-3. _____ is fundamental symbolic unit
1. Perisylvian
2. Left
3. Phoneme
Motor (speech output): 1. _____ area (____) and links to 2. _____ and _____ cortex
1. Broca's area (44, 45)
2. premotor and motor cortex
Sensory (language comprehension) : 1. _____ area (____) and links to 2. _____, _____, and _____ cortex
1. Wernicke's area (22)
2. auditory, visual, and somatosensory association cortex
_____ links Broca and Wernicke areas. All connections are bi-directional <-->
Arcuate fasciculus
Conduction aphasia:
1. Speech?
2. Phonemic paraphasias?
3. Comprehension?
4. Repetition?
1. Non-dysarthric speech, fluent
2. Phonemic paraphasias (phonemic substitutions)
3. Comprehension intact
4. Repetition impaired
Conduction aphasia:
-Traditional interpretation: impaired conduction of neural impulses from Wernicke's and Broca's areas via 1. _____, resulting in inaccurate translation of word representations into speech
-Current interpretation: entire 2. _____ represents hierarchical processor converting words into speech.
-Comprehension intact because Wernicke's area and associated sensory links are intact
1. arcuate fasciculus (part of superior longitudinal fasciculus)
2. perisylvian language cortex
Attempts to explain a single word by other means.
Circumlocution
Type of aphasia?
-Non-dysarthric speech, fluent
-Word-finding difficulty
-Semantic paraphasic errors (uses wrong words)
-Comprehension impaired
-Repetition unimpaired
Transcortical sensory aphasia
Type of aphasia?
1. Non-dysarthric speech, fluent
2. Phonemic paraphasias (phonemic substitutions)
3. Comprehension intact
4. Repetition impaired
Conduction aphasia
Transcortical sensory aphasia:
-Isolation of perisylvian cortex language processor from sensory association cortices supporting meaning
-Results in difficulty matching words to cortical sensory representations, so both _____ and _____ of speech is impaired
-Repetition is intact because the core phonologic processing circuitry is intact (Broca's and Wernicke's areas are spared)
generation and comprehension
Type of aphasia?
-Fluent, non-dysarthric speech
-Phonemic paraphasia, semantic paraphasic errors
-Impaired comprehension
-Impaired repetition

In effect, transcortical sensory aphasia + conduction aphasia
Wernicke's aphasia
Dysarthric speech:
1. What is it?
2. When is it exhibited?
1. labored, slurred speech with broken syllables
2. only during Broca's aphasia
Type of aphasia?
-Difficulty generating speech; labored, slurred (dysarthric)
-Comprehension intact
-Repetition impaired
Broca's aphasia
Cannot point to objects named or name objects
Apperceptive visual agnosia
Inability to carry out specific actions on command (e.g., use of tools)
Apraxia
Apraxia Anatomical components:
1. _____ cortex (recognizing the tool; representation in "what" system)
2. _____ cortex (naming the tool; representation in the language system)
3. _____ cortex (mind's eye image of tool movement in "where" system)
4. _____ cortex (mind's hand and arm representation of using the tool)
1. Ventral visual association cortex
2. Left perisylvian cortex
3. Dorsal visual association cortex
4. Premotor cortex
Condition?
-Body part-as-tool errors
-Unable to pantomime use of tool
-Can recognize correct use of tool
Ideomotor apraxia
Neuroanatomical basis of associative learning:
-Decortication fails to abolish 1. _____
-Lesions of cerebellum ipsilateral to trained eye abolish 2. _____ and prevent re-learning.
-Critical region is 3. _____ and _____ nuclei of cerebellum (deep cerebellar nuclei)
-4. _____ and _____ activity are not required for CR expression.
1. Conditioned response
2. Conditioned response
3. medial dentate and interpositus nuclei
4. Hippocampal and cortical activity
Associative Learning: Classical (Pavlovian) Conditioning:
-4 Targets:
-An initially neutral stimulus becomes a conditioned stimulus (CS), able to elicit a conditioned response (CR), through repeated temporal pairing with an unconditioned stimulus (US), that elicits an unconditioned response (UR).
- 3 Examples:
1. smooth muscle, cardiac muscle, glands, reflexive skeletal muscle
2. salivation, cardiac acceleration, eyeblink
Instrumental Learning (Operant learning):
-Target is a 1. _____ response, technically referred to as an "2. _____."
-Differs from associative (Pavlovian) learning in that voluntary behavior (R) is modified in form and frequency according to the stimuli (S) produced by the behavior itself.
-Associative = 3. ___; Instrumental = 4. ___.
Neural processes and their localization differ for S-S and S-R type learning.
1. voluntary skeletal muscle
2. Operant
3. S-S (stimulus-stimulus)
4. S-R (stimulus-response)
Instrumental Learning: Reinforcement:
-By definition, reinforcement describes a situation when the frequency of a response (voluntary behavior) is increased following the introduction or withdrawal of a particular stimulus.
-The stimulus modifying the response frequency can be considered a _____
-Primary reinforcing stimuli (e.g. food, water, sex) have direct biological relevance and intrinsic reward/incentive value
Reinforcer
Neuroanatomical basis of instrumental learning/reinforcement:
-At least 20 brain sites act as reinforcers when stimulated
-Medial forebrain bundle (anterior, posterior and lateral hypothalamus)
-Mesolimbic DA system activation critical: (3)
1. ventral tegmental area (VTA)
2. nucleus accumbens
3. prefrontal cortex
Neuroanatomical basis of instrumental learning/reinforcement:
-Lesion or pharmacological blockade of reinforcement pathway:
- abolishes self-stimulation
- "extinction" of reinforced behavior
- _____ (inability to experience hedonic effect of primary reinforcers)
Anhedonia
Short-term memory (STM):
-"Working memory" function ascribed to 1. _____
-Differs from STM in that information is available for cognitive manipulation
-Various STM registers involve other parts of cortex, e.g. :
- 2. Speech-associated STM (_____)
- 3. Visuospatial (2)
1. prefrontal cortex
2. premotor cortex
3. striate cortex; parietal cortex
Long-term memory (LTM):
-Days to years
-Requires structural/molecular basis for explanation
-3 Stages of formation: (location)
1. Encoding (medial temporal lobe - Hippocampus)
2. Storage (association cortex)
3. Retrieval - requires both medial temporal lobe and association cortex
Levels of memory processing:
-Sensory Register
-Short-term memory (1. _____)
=Long-term memory (2. _____)

-These divisions have meaning in terms of both information processing and their neurological bases
1. primary
2. secondary
Short-term memory:
-Seconds to minutes (usually)
- Time is not key
-Classically, limited to 1. _____ (words or patterns)
-Instantly accessible
-Can be maintained indefinitely by 2. _____
- Disrupted by 3. _____
-Digit span (neuropsych. test) (immediate in MLM)
1. 7 bits
2. rehearsal
3. interference
LTM and STM vs remote, recent and immediate memory:
-Long-term memory names a 1. _____ and refers to permanence; LTM is permanent but STM is not.
-Remote memory 2. _____ memory for events more remote in time (i.e., childhood, school, etc), versus recently acquired information that may or may not become permanent.
-With certain lesions that impair LTM but not STM, 3. _____ memory is relatively intact, whereas 4. _____ memory is impaired. - Lesion 5. _____
- Pass digit span test - Cannot repeat anything at the end of conversation
-Recent memory and STM are often misapplied. -Consider the difference between STM and recent memory carefully when making inferences and answering questions.
1. process
2. describes
3. remote
4. recent
5. Hippocampus
2 forms of long-term memory:
1. Explicit (declarative)
2. Implicit (non-declarative)
Explicit (declarative) LTM:
Facts/Events -> Medial temporal lobe (hippocampus)
Implicit (non-declarative) LTM:
1. Priming (S-S type conditioning) -> Neocortex
2. Procedural (Habits & skills) -> Striatum
3. Associative learning (classical & operant conditioning)
-> Emotional responses -> Amygdala
-> Skeletal musculature -> Cerebellum
4. Non-associative learning (habituation & sensitization) -> Reflex pathways
Declarative (explicit) LTM:
Memory for facts (1. _____)
Memory for events (2. _____)
3. _____ memory
Memory that is capable of being 4. _____ (in humans).
Type of memory disrupted by lesion of the 5. _____*
* Note that bilateral damage to the 6. _____ is required!
1. semantic
2. episodic
3. conscious
4. verbalized
5. medial temporal lobe
6. hippocampus
The 1. _____ is necessary for formation of LTM for 2. _____ information.
Non-hippocampal systems are involved in 3. _____ LTM and STM
1. hippocampus
2. declarative (explicit)
3. non-declarative
Neurobiological Mechanisms of LTM:
Active process with time-course.
Ability of electroconvulsive shock to produce retrograde amnesia is time-dependent.
90-95% inhibition of brain protein synthesis selectively disrupts 1. ___ but not 2. ___.
1. LTM
2. STM
Neurobiological mechanisms of LTM: Long-term potentiation (LTP):
LTP=Increase in strength of a synaptic response following electrical stimulation. May last indefinitely.
Alters biochemistry of 1. _____ receptors and initiates molecular cascade culminating in synthesis of new proteins and growth or pruning of synaptic connections.
Produced by brief high-frequency stimulation of neurons of the 2. _____, _____, and _____ collateral pathways of the 3. _____.
1. NMDA-type glutamate receptors
2. perforant, mossy fiber, and Schaffer
3. hippocampus
1. Main cortical inputs to hippocampus
2. Main output from hippocampus
1. Entorhinal cortex and perforant pathway
2. Subiculum
_____ is highly vulnerable to degeneration in Alzheimer's Disease
Entorhinal cortex
Hippocampal/cortical circuitry
Slide 29 - 2nd lecture
Neurotransmitter systems involved in memory:
Glutamatergic (1. ___)
2. 2 Cholinergic:
3. 2 Norepinephrine:
GABA
1. Long-term potential (LTP)
2. basalo-cortical and septo-hippocampal pathways
3. locus ceruleus, dorsal bundle
Bilateral lesion of hippocampus & Medial Temporal Lobe (MTL) causes:
1. Complete anterograde amnesia for explicit/declarative information
2. Impaired spatial memory (can't find way through house)
Memories are stored where?
Distributive representations
Corticobulbar tracts pass through _____ limb of internal capsule and middle part of crus cerebri (cerebral peduncles)
Posterior
Basal ganglia motor system:
1. Major site of INPUT is _____
2. Major site of OUTPUT is _____
3. GPi sends its inhibitory output to thalamic nuclei in fiber tracts (known as the ansa lenticularis, and lenticular fasciculus a.k.a. H2 fields of Forel) that run through or around the internal capsule
4. None of the Corpus Striatum projects directly to the spinal cord. However, the GP projects to the 3. _____, which then projects via the 4. _____ tract to the spinal cord where it modulates 5. _____ muscle tone.
1. Striatum
2. GPi
3. red nucleus
4. rubrospinal tract
5. flexor
Which cerebellar peduncle is responsible for output?
Superior cerebellar peduncle
With the exception of the _____, the midline portions of the cerebellum tend to project to midline deep cerebellular nuclei and the more lateral portions tend to project to their correspondingly more lateral deep cerebellular nuclei.
flocculus/nodulus
_____ cells are the only excitory cells in the cerebellular cortex.
Granule cells
Which nucleus projects from each portion of the cerebellum?
1. vermis
2. intermediate zone (medial part of hemispheres)
3. Lateral hemispheres
1. fastigial
2. globose and emboliform
3. dentate
Globose and emboliform nuclei are collectively refered to as?
interpositus
floccular/nodular lobe projects upon the _____ nuclei (in the medulla)
vestibular nuclei
Cerebellar Input/Afferents:
1. 4 via Inferior cerebellar peduncle
2. 1 via Middle cerebellar peduncle
1. Ipsilateral Dorsal Spinocerebellular Tract (proprioceptive inputs from body)
Ipsilateral Cuneocerebellar Tract
Contralateral Olivocerebellular (Brain stem) Tracts (proprioceptive input from whole body via the inferior olive)
Vestibulocerebellular (from vestibular nuclei)
2. Contralateral Pontocerebellular (from Pontine Nuclei, which receive input from many areas of cortex)
Cerebellar output/efferents:
1. Via superior cerebellar peduncle
1. Contralateral Dentatorubrothalamocortical tract (terminates in VL nucleus of thalamus (some indirectly via red nucleus), then relayed to cortex)
3 types of aminergic fibers to the cerebellum:
1. Climbing fibers
2. Mossy fibers
3. Aminergic fibers
Climbing fibers
a. originate in _____
b. synapse on _____
c. send collaterals to _____
1. Inferior olive
2. Purkinje cells
3. Deep nuclei
Mossy fibers
a. originate from a variety of tracts (3)
b. synapse on _____
c. send collaterals to _____
1. spinal cord, vestibular, and pontine nuclei
2. Granule cells
3. Deep nuclei
Aminergic fibers
a. _____ (noradrenergic)
b. _____ (serotonergic)
1. Locus ceruleus
2. Raphe nucleus
Both climbing and mossy fibers provide _____ input. The aminergic inputs modulate cerebellular activity.
Excitatory
For each, list Input synapses on to Cell Type and Cell Type Activity and Projects to:
1. Excitatory climbing fibers:
2. Excitatory mossy fibers:
3. Excitatory granule cell parallel fibers:
4. Excitatory granule cell parallel fibers & mossy fibers
1. Purkinje; Inhibit deep nuclei
2. Granule; Excite Purkinje cells
3. Basket/Stellate; Inhibit Purkinje
4. Golgi; Inhibit Granule
Basket, stellate and golgi cells are all _____
interneurons
1. _____ cells provide primary inhibitory (GABAergic) output of the cerebellular cortex by projecting to the 2. _____ deep nuclei (esp. dentate nucleus).
1. Purkinje cells
2. ipsilateral
5 Contents of Molecular layer of cerebellum:
a. stellate cells
b. basket cells
c. Dendrites from Purkinje cells
d. bifurcated (T-shaped) parallel fibers
from granule cells
(synapse on Purkinje cell dendrites)
e. Dendrites of golgi cells
2 Contents of Purkinje cell layer:
a. Purkinje cells (cell bodies)
b. basket cell projections
3 Contents of Granule cell layer:
a. granule cells
b. golgi cells (cell bodies)
c. mossy fiber (glomeruli)
synaptic connections
4 Functions of the Cerebellum:
1. Coordination of Voluntary Motor Activity - by influencing muscle activity
A. fine skilled movements
B. gross propulsive movements (i.e., walking)
2. Maintenance of posture and balance (equilibrium) - via connections with the vestibular system
3. Maintenance of muscle tone - via connections to the spinal cord (gamma motor neurons)
4. Motor Learning and Memory (e.g., stereotyped movements)
6 Signs of cerebellar dysfunction:
1. Hypotonia
2. Ataxia
3. Dysmetria
4. Dysdiadochokinesia
5. Rebound Phenomena
6. Intention Tremor
Failure to place an extremity at a precise point in space (e.g., touching heel to shin or finger to nose)
Dysmetria (past pointing)
Failure to make rapid alternating movements (e.g., rapidly and alternately touching the backhand and palm of one hand to the other hand).
Dysdiadochokinesia
Loss of normal checks of agonist and antagonists muscles (e.g., if you hold a patient's arms that are held tense away from their chest and then let go of, then they will fly towards the chest).
Rebound phenomena
Tremor that occurs when attempting a voluntary movement (e.g., reaching for a glass). Note that intention tremors can also occur in Parkinson's disease
Intention tremor
Unilateral lesions of the cerebellum produce ipsilateral motor deficits (e.g. falling toward the side of the lesion). Degeneration of the vermis due to alcoholism is _____.
bilateral
Vestibulocerebellular
1. Cerebellar cortex area
2. Associated functions
3. Damage results in:
1. Flocculi &Nodulus
2. Equilibrium & Coordinated movement of head and eyes
3. Falling (ipsilateral) &Nystagmus
Spinocerebellular
1. Cerebellar cortex area
2. Associated functions
3. Damage results in:
1. Vermis & Medial part of hemispheres (intermediate zone)
2. Stereotyped and propulsive movement like walking.
3. Truncal Ataxia "Drunken" gait
Corticocerebellular
1. Cerebellar cortex area
2. Associated functions
3. Damage results in:
1. Lateral (bulk) of the hemispheres
2. Coordination of fine movement
3. Dysdiadochokinesia
Dysmetria (e.g. Past Pointing)
Ataxia of extremities
Asynergy
Corticocerebellular input is indirect via the _____ nuclei.
Pontine nuclei
_____ (embryonic tumor) specifically affects vestibullocerebellum and results in falling and nystagmus. If the lesion is unilateral the sign will be on the ipsilateral side.
Medulloblastoma
Some Dyskinesias:
1. _____ - ceaseless occurrence of slow , sinuous writhing movements preformed involuntarily and especially severe in the hands. (pill rolling)
2. _____ - ceaseless occurrence of a wide variety of rapid, highly complex, and jerky movements that appear to be well coordinated but are involuntary.
3. _____ - rhythmic oscillating movements.
4. _____ - unsteady movements, inability to coordinate voluntary muscle movements.
5. _____ - loss of coordination
1. Athetosis
2. Chorea
3. Tremor
4. Ataxia
5. Asynergy
_____ - disorder tonicity of muscles. Contortions of the muscles of the truck and extremities. Usually relates to posture.
Dystonia
The basal ganglia nuclei
a. caudate - major site of input (from _____ and _____)
b. putamen - major site of input (from _____ and especially _____)
c. globus pallidus (GPi) - major source of output (to _____)
1. Cortex and SNc
2. Cortex and SNc
3. Thalamus
The globus pallidus is split by a _____ into interior and exterior portions called GPi and GPe, respectively.
Medullary lamina
Caudate, putamen and globus pallidus are collectively referred to as the _____
Corpus (body) striatum (striped)
The pyramidal neurons in the cerebral cortex become the pyramidal tracts, e.g., these are the corticospinal and some of the corticobulbar tracts. That is fiber tracts of pyramidal neurons become (part of) the 1. _____, which becomes (part of) the cerebral peduncles, which pass through the pons and become the 2. _____.
1. Internal capsule
2. Pyramids
Internal capsule Anterior limb
a. separates the head of the caudate
and lenticular nucleus
b. contains 3 fiber tracts:
1. thalamocortical & corticothalamic
2. frontopontine
3. transverse fibers from the caudate to putamen
Internal capsule Posterior Limb contains the following fiber tracts
-3 In anterior portion:
-In posterior portion
- sensory fibers (from PL nucleus of thalamus to postcentral gyrus)
1. corticospinal
2. corticobulbar
3. corticorubral (frontal lobe to red nucleus)
*****FAL (Face, Arm, Leg)
A lacunar infarct in the anterior part of the posterior limb will produce a _____.
"pure motor" stroke
Direct and Indirect Motor Loops
...
1. _____ disease - bilateral degeneration of dopaminergic neurons in the substantia nigra pars compacta that project to the striatum (2. _____ pathway)
1. Parkinson's disease
2. Nigrostriatal pathway
1. _____ disease - bilateral degeneration of GABAergic neurons in the striatum that project to the substantia nigra pars reticulata (2. _____ pathway)
1. Huntington's disease
2. Striatonigral pathway
Hemiballism - _____ damage to subthalamic nucleus
contralateral
Blocking output from the ___ or ___ relieves the symptoms of Parkinson's Disease
1. STN
2. GPi
In Parkinson's disease, Loss of dopaminergic input into the striatum results in enhanced _____ of the thalamus which underexcites the motor cortex
inhibition
Surgical treatment strategy for Parkinson's disease:
1. _____ - lesioning of the GPi (reduces excessive inhibition of the thalamus, which results in enhanced stimulation of the cortex)
2. Lesioning of the _____ nucleus.
1. Pallidotomy
2. STN
3 Drug treatments for Parkinson's disease:
1. (muscarinic) anticholinergics (useful in early stages) - inhibitory dopaminergic control of cholinergic interneurons in striatum is lost in PD and blocking muscarinic receptors prevents the overactivity of the cholinergic interneurons.
2. Levodopa (L-DOPA) - a dopamine precursor that restores the lost dopamine. Given in combination with carbidopa (an peripheral AAAD inhibitior) so that L-DOPA is not convert to dopamine in the periphery.
3. selegiline - an MAOB inhibitor that prolongs the actions of dopamine, by preventing is degradation.
If unilateral lesion -> _____ damage.
contralateral
Action of carbidopa and why it's given with Levodopa (L-Dopa) treatment of Parkinson's disease.
Inhibits Aromatic AA Decarboxylase (AAAD) which converts L-DOPA to DA in the periphery and causes nausea
Action of selegiline and why it's used to treat Parkinson's disease.
Inhibits Monoamine oxidase B which breaks down DA
3 Signs of Huntington's disease:
a. choreaform movements (rigidity if early onset) - due to loss of GABAergic neurons
b. cognitive dysfunction
c. psychiatric dysfunction (often depression)
Huntington's disease is Due to a loss of striatal GABAergic (and come cholinergic) neurons in the caudate and putamen (_____ pathway)
Striatonigral pathway
A direct pathway from the motor cortex to motor neurons of the spinal cord exist only for muscles of the _____
Distal extremities
Corticospinal tract fibers:
1. Arise from sensorimotor cortex
a. 55% motor/premotor areas 4, 6 (frontal lobe)
b. 35% sensory 3,1,2 (postcentral gyrus of parietal lobe)
c. 10% other cortical areas
d. only 1. ____% specifically from large pyramidal (Betz cells) from layer V of area 4
2. Tracts originating from the frontal lobes subserve motor function
3. These fiber tracts terminate or send collaterals to 3:
1. 5%
a. thamalus (VL nucleus)
b. brains stem (reticular formation, pontine and cranial nuclei)
c. spinal cord (motor neurons in anterior horn and interneurons)
Corticospinal tract fibers (cont'd)
5. The fibers passes through the pyramids
of the medulla
a. ~87% of the fibers decussate in
pyramids descend in the lateral column
of the spinal cord
b. ~3% do not cross and descend in
the lateral column of the spinal cord
- these ipsilateral fibers control muscles
of the 1. _____ and _____; they are
involved in maintaining an upright posture
and gross position of the limbs.
c. ~10% descend in the _____ column
of the spinal cord and decussate at lower
cord levels close to their destination.
6. There is somatic organization of the
pyramidal tracts.
1. trunk and proximal limbs
2. anterior
Corticobulbar tract fibers terminate in brain stem nuclei (2)
1. somatic efferent nuclei
2. brachial efferent nuclei
Striato-striatal Loop:
(striatonigral-GABAergic) striatum > ___ then ___ > striatum (nigrostriatal -DAergic)

(Huntington's and Parkinson's diseases, respectively)
SNr then SNc
Subcortical Descending Systems/Pathways:
1. Rubrospinal (red nucleus to spinal cord) - modulates _____ muscle tone (coordinates with corticospinal to control hand and finger movement). Synapses on interneurons.
2. Vestibulospinal (brain stem vestibular nucleus to spinal cord) - modulates _____. Most synapses are on interneurons, which then project to alpha and gamma motor neurons, some synapses are directly onto _____ muscle motor neurons.
3. Tectospinal (midbrain tectum to spinal cord) - controls reflex movements of the upper trunk, neck and eyes in response to visual stimuli. Synapses on interneurons at the cervical levels.
4. Reticulospinal (reticular formation to spinal cord). Synapse on interneurons and _____ motor neurons.
1. Flexor
2. equilibrium/balance; extensor
4. gamma
Decerebrate rigidity occurs when the posterior portion of brain stem is severed by injury to the superior border of the pons. This results in increased 1. _____ tone in all muscles (trunk, limbs and neck), because cortical and basal ganglia inhibitory influence to the spinal cord are blocked, but the 2. _____ and _____ excitatory influences remain intact. The end result is increased activity to extensor muscles
1. extensor tone
2. vestibulospinal and reticulospinal
Tract gives input to what nucleus/area?
What does that nucleus/area control?
1. Cerebrocerebellar tract
2. Vestibulocerebellar tract
3. Spinocerebellar tract
1. Dentate nucleus; extremities
2. Flocculus/nodulus; balance/equilibrium
3. Vermis/Intermediate; gait
2 Corticosubthalamic Loops:
1. Indirect motor loop
2. Cortex > STN > GPi >Thalamus > Cortex
Vestibulo- , tecto-, and reticulospinal pathways have a very limited role on the control of 1. _____, and instead control
muscules of the 2. _____.
1. extremities
2. trunk
Examples of "Lower Motor" Neuron Lesions
1. _____ - viral disorder that kills motor neurons
2. _____ - a degenerative motor neuron disease of varying time of onset and severity
a. infantile form (Werdnig-Hoffman disease) - death
b. juvenile form (Kugelberg-Welander disease) - disability
3. Spinal cord tumor (mass lesion effect)
4. Herniated disk
1. poliomyelitis
2. spinal muscular atrophy
Cerebral palsy is technically an ___ disorder due to damage to cerebral cortex in utero. Characterized by spastic paralysis, BUT a variety of other signs may be present including rigidity, tremor, ataxia, athetosis, speech disorders and sometimes mental retardation.
1. UMN
Muscular or Neuromuscular Junction Disturbance:
Examples include:
1. _____ - autoantibodies to AChR characterized by fatigue, weakness and inability to sustain muscle contraction (esp. eyes and mouth) and that resolves after rest.
2. _____ - a group of hereditary neuromuscular disorders (caused by mutations in the chloride, sodium or potassium channels that affect the muscle membrane) and characterized by slow relaxation of muscles after a contraction. Described as "stiffness" (e.g., difficulty releasing ones grip like after a handshake).
1. Myasthenia gravis
2. Myotonia
organ of Corti -> (N1) 1. _____ in inner ear -> 2. _____ -> (N2) ventral & dorsal 3. _____ nuclei in pontomedullary junction -> MOST axons cross to opposite side and ascend as the 4. _____ -> (some fibers synapse on the 5. _____) -> the rest continue on as the 6. _____ -> 7. _____ in the midbrain -> most fibers travel in brachium of inferior colliculus to (N3) 8. _____ in the thalamus -> auditory radiation in sublenticular part of posterior limb of internal capsule -> transverse temporal gyrus of Heschl in the temporal lobe (9. name and area)
1. Spiral ganglion
2. cochlear nerve CN VIII
3. cochlear nuclei
4. lateral lemniscus
5. superior olivary nucleus
6. lateral leminiscus
7. inferior colliculus
8. medial geniculate nucleus
9. primary auditory cortex, area 41
Most of the axons of the cochlear nuclei of one side 1. _____. Therefore each auditory cortex receives impulses from both ears but more from the 2. _____ side.
1. cross over
2. opposite
1. Damage to the cochlear nerve or nuclei of one side -
2. Damage to lateral lemniscus up to primary auditory cortex -
3. Damage to adjacent auditory association area -
1. Total sensorineural deafness in ear of affected side.
2. Partial sensorineural deafness in both ears but more in the opposite side.
3. Able to detect tones and patterns, but unable to comprehend their meaning.
Transverse temporal gyrus of Heschl is another name for?
Primary auditory cortex, area 41
Brodmann's area 42
Secondary auditory cortex (association area)
Interconnections exist between the various relay neurons - essential for _____.
Accurate sound localization
Descending fibers are bilateral and end on neurons at different levels of the auditory pathway and on the hair cells of the organ of Corti (olivocochlear bundle of Rasmussen).
• It is believed that these fibers serve as a feedback mechanism and inhibit the reception of sound.
• They may also have a role in the process of 4. _____, suppressing some signals and enhancing others.
1. Olivochochlear bundle of Rasmussen
2. Feedback
3. Inhibit
4. Auditory sharpening
Reflex contraction of tensor tympani
• dampens vibrations of tympanic membrane
• via connections between?
superior olivary nucleus and trigeminal nucleus
Reflex contraction of stapedius
• dampens vibrations of the footplate of the stapes on the oval window
• via connections between?
superior olivary nucleus and facial motor nucleus
1. _____ reflex - generalized jerking of body in response to loud, sudden sound; via fibers projecting from inferior colliculus to motor neurons in the spinal cord level (2. _____ tract)
1. Startle reflex
2. tectospinal tract
1. _____reflex - blinking of the eyelids in response to sound
- pathway via fibers projecting from inferior colliculus to the motor nucleus of CN VII (2. _____ tract)
1. Auditory-palpebral reflex
2. tectobulbar tract
1. _____ reflex - deviation of eyes toward direction of sound; via fibers projecting from inferior colliculus to nuclei of CNs III, IV, and VI (2. _____ tract)
1. Auditory-oculogyric reflex
2. tectobulbar
Weber test:
• unilateral conduction deafness - sound perceived where?
• unilateral sensorineural deafness - sound perceived where?
1. in the ear with the conductive hearing loss, i.e. if the right has a conductive loss, the sound lateralizes to the right ear
2. in the ear with the better cochlear, i.e. if the right ear has a sensorineural loss, the sound lateralizes to the left ear.
Rinne test:
• normal - air conduction is better than bone conduction; termed Rinne's 1. _____ or may be written as AC > BC
• unilateral conduction deafness - bone conduction is heard more clearly than air; termed Rinne's 2. _____ or may be written as BC > AC
• "true" Rinne's negative - patient has 3. _____ deafness in tested ear
• "false" Rinne's negative - patient has _____ deafness in tested ear, but can hear the sound in the non-tested ear due to transfer of sound through the skull base
1. positive
2. negative
3. conduction
4. sensorineural
_____ - ringing or clicking sound in the ears in the absence of auditory stimuli; one of the first symptoms of cochlear nerve degeneration; may occur as a result of infections of the middle or inner ear or as a side effect of medication
Tinnitus
Utricle and Saccule
• contain the sensory receptors for static equilibrium called 1. _____
• macula in 2. _____ -respond to horizontal movements of the head, i.e., forward and backward, side to side
• macula in 3. _____ - respond to vertical movements of the head, i.e., upward/downward
1. macula
2. utricle
3. saccule
Semicircular Canals and Ducts
• semicircular canals - arranged at right angles to each other so that all 3 planes in space are represented: anterior for 1. _____ plane, posterior for 2. _____ plane, lateral for 3. _____ plane
• 4. _____ - prominent enlargement located at one end of each semicircular canal
• ampullary portion of each duct contain the sensory receptors for dynamic equilibrium called 5. _____
• receptors respond to dynamic equilibrium - 6. _____ or _____
1. coronal
2. sagittal
3. horizontal
4. ampulla
5. crista ampullaris
6. angular acceleration or rotational movements of the head
_____ ganglion - peripheral processes connected with receptors; central processes become the vestibular nerve and joins the cochlear nerve as CN VIII
Vestibular (Sarpa's) ganglion
VESTIBULAR PATHWAYS - for balance and orientation in space:
maculae and cristae -> (N1) 1. __ ganglion -> 2. __ -> (N2) 3. __ nuclei at boundary between medulla and pons:
a. -> cerebellum (via 4. __ fibers) - for regulatory mechanisms for control of 5. __, __, & __
b. -> cerebral cortex (via 6. __, __, & __ along 7. _____ fibers) - for conscious perception of movement and orientation in space, in conjunction with the visual and somatosensory systems
c. -> motor nuclei of cranial nerves III, IV, VI (via 8.__) - for coordination of eye movements with head and/or body movements
d. -> motor neurons in spinal cord (via 9. __ fibers) - for influencing muscle tone and producing reflex postural adjustments of the head and body
1. vestibular ganglion
2. vestibular n. (CN VIII)
3. vestibular nuclei
4. vestibulocerebellar fibers
5. eye and head movements and posture
6. cerebellum, red nucleus, and thalamus
7. dentato-rubro-thalamo-cortical fibers
8. MLF
9. vestibulospinal fibers
VESTIBULAR NYSTAGMUS - compensatory eye movements that occur during and immediately with large head rotations, e.g. 360 body turn; may be vertical or horizontal
• 2 Phases (during rotation)
- slow phase - slow drifting of the eyes in the direction 1. __ the head rotation, as though fixed on some object in the environment
- fast phase - rapid jump 2. __ direction of rotation to establish new fixation point
• when rotation stops - the eyes continue to move slowly in the direction of the previous spin, then jerk rapidly in the opposite direction
• nystagmus movement - named for direction of the 3. __ phase, leftward-beating nystagmus, downward-beating nystagmus
• often accompanied by vertigo (dizziness)
1. opposite
2. toward
3. fast
1. _____ - used as a diagnostic indicator of the integrity of the vestibular system, i.e., in patients complaining of vertigo
a. either warm (40C/104F) or cold (30C/86F) water is introduced into the external auditory canal
b. normal response: cold water induces nystagmus 2. ____ from tested ear; warm water induces nystagmus 3. ____ tested ear
1. Caloric test
2. away
3. toward
COWS - Cold Opposite, Warm Same
Condition?
pathophysiology not well understood
abnormalities in the posterior semicircular canal have been implicated, i.e., otolith from the utricle separate from the otolith membrane -> lodge in the cupula of the posterior semicircular canal making the cupula more dense -> produces abnormal deflections of the cupula when the head changes position relative to gravity
characterized by brief episodes of vertigo that coincide with particular changes in body position
may be triggered by turning over in bed, getting up in the morning, or rising from a bent position
Benign positional vertigo
Cause: increase in endolymph volume within membranous labyrinth (endolymphatic hydrops); bilateral in 50% of cases
R/O TIA 2o to basilar artery stenosis

Occurrence of attacks unpredictable and repeated

Manifestations: severe recurent vertigo, nausea and vomiting, disturbances in balance (almost impossible to stand and stay erect), tinnitus, progressive deafness

Management: ENT referral
anti-motion sickness drugs
low-salt diet - to reduce endolymph production)
surgery - drain excess endolymph or removal of involved labyrinth in patients with complete hearing loss
Meniere's syndrome
Vitreous of the eye:
Vitreal components include salts, sugars, collagen fibers, and _____ which serve to remove debris (phagocytic) in the visual field and are derived from cells of the _____.
1. Hyalocytes
2. bone marrow (monocytes)
Retina:
The human retina consists of 6 different types of neurons and a major glial cell.
1. _____ are found in the innermost layer of the retina that surround blood vessels.
2. The _____ cell extends from the inner limiting membrane to the outer limiting membrane and functions primarily in structural and trophic support of the retinal cells.
1. Astrocytes
2. Mullerian glial cell
Retinal Pigment Epithelium (RPE)
1. The RPE cells are interconnected by _____ junctions and ___ junctions.
2. These cells are positioned between the sensory retina and the choroid, which normally contain _____ granules.
These cells play a significant role in the development and maintenance of the sensory retina, particularly the photoreceptors.
3. The RPE forms an important structural relationship with _____ membrane allowing transport to and from the choriocapillaris.
1. tight; gap
2. Melanin granules
3. Bruch's membrane
Retinal Pigment Epithelium (RPE)
RPE cells form a structural interaction with the outer segments of photoreceptors and secrete a multitude of growth factors that promote the differentiation and survival of photoreceptors.
1. RPE cells also _____ shed photoreceptor OS and recycle _____.
The RPE phagocytic function is critical to maintain the life of cone and rod photoreceptor cells.
1. Phagocytize; retinoids
Photoreceptor cells
1. The connecting _____ connects the OS to the inner segment, which contains mitochondria, synthesizes OS membrane proteins, and produces the energy that maintains the cell.
2. The _____ (nucleus) of all photoreceptors are found within the outer nuclear layer (ONL).
The axon of the rod and cone photoreceptor synapses with a dendrite(s) of a bipolar neuron (cell) in the outer plexiform layer.
1. Cilium
2. Perikarya
Rod photoreceptors:
Through a process of rod shedding, outer segments are constantly being renewed.
New discs are formed at the base of the OS and move outward so that the shed discs are replaced.
1. This process results in the rod OS being of _____ length.
2. Rod OS renewal occurs about every __ days, 3. while cone OS renewal occurs every __ days.
1. constant
2. 10 days
3. 30 days
Rod photoreceptors:
1. The photopigment rhodopsin consisting of a _____ and _____ is embedded in the rod outer segment.
2. Rhodopsin is highly sensitive to photons of light, however, rods stimulation results in low _____.
1. Chromophore and opsin protein
2. visual acuity
Rod photoreceptors:
Several rods may synapse with dendrites of bipolar neurons.
Rods are found throughout the retina, including the _____, but not in the fovea centralis.
Rods predominate in all other regions of the retina, are 1000 times more sensitive than cones and are much better motion detectors than cones.
macula
********Cone photoreceptors:
The cone OS is not enclosed with a second membrane, but are open to the extracellular (subretinal) space adjacent to the RPE.
Unlike rods, axons of a cone photoreceptor synapse with a _____ bipolar neuron and, in turn, to a single ganglion cell.
*****Single
*****Cone photoreceptors:
The process of transduction in cones is similar to that of rods.
1. Cone opsins (3) absorb photons of light and undergo a conformational change, which results in _____.
2. This hyperpolarization is propagated to the cones synaptic ending, the _____, in the OPL.
3. As for rods, synapses of cones release _____ tonically in the dark and respond to light with a _____ in glutamate release.
1. hyperpolarization
2. Cone pedicle
3. Glutamate
4. Decrease
Function of cone receptor cells:
Cone photoreceptors do not signal color, but only signal the presence of light in the visual field.
A single cone photoreceptor does not detect the color (wavelength) or intensity of light.
The visual system computes color by comparing across a population of photoreceptors and intensity by determining how many photoreceptors are responding to that light source.
This mechanism allows _____ color vision in humans.
Trichromatic
Cone photoreceptors:
There are three types of cones named for the different wavelength of light that it maximally responds to.
1. _____ cones (64%, L-cones) are sensitive to long wavelengths, _____ cones (32%, M-cones) are sensitive to medium wavelengths, and _____ cones (2%, S-cones) are responsive to short wavelengths.
4. _____ and _____ cones are concentrated in the fovea centralis, and _____ are found outside the fovea.
6. Which color cones are the most sensitive?
1. Red cones
2. Green cones
3. Blue cones
4. Red and green
5. Blue
6. Blue
Color Blindness:
Color blindness is an inaccurate term for a lack of sensitivity to certain colors. Absolute color blindness is rare.
Color blindness is a result of a lack of one or more of the types of color receptors.
1. _____ color blindness is the most common form (99%)
About 8-12% of males have a color perception defect, but this is rare in females (<0.5%).
2. _____ color blindness is the second most common form, but is rare.
3. It is also possible to have the color receptors missing entirely, which would result in _____ vision.
1. Red/green
2. Yellow/blue
3. Black and white
Color Blindness:
1. The genes for the red and green opsins are located on the __ chromosome, thus, color blindness is more common in males.
2. _____ is a form of dichromatism in which red receptors are lost. It exists in 1% of males and is sex linked.
3. _____ is a condition in which green receptors are lost affecting red-green hue discrimination. It is present in 1% of males and is sex linked.
1. X
2. Protanopia
3. Deuteranopia
Color Blindness:
1. _____ (0.01%) is a rare, hereditary color vision in which two pigments are present but with a total loss of blue receptors. This is a form of dichromacy.
2. _____ is a condition in which one of cone 3 pigments is altered in spectral sensitivity resulting in impairment, not loss.
3. _____ is total color blindness and lack the ability to distinguish colors caused by a cone defect or loss. This condition is caused by loss of 2 cone receptors.
1. Tritanopia - NOT sex linked; Blue is on Chromosome 7, not X
2. Trichromacy
3. Monochromacy
Individuals with _____ cannot perceive differences between red, orange, yellow, and green. These colors appear similar in these people.
Dichromacy
Macula lutea and Fovea centralis:
1. At the posterior pole of the eye is a yellow-appearing region, the _____.
2. The color is produced by _____ pigments in the _____ in a region 2mm in diameter centered on the fovea.
4. At the center of the macula is the _____.
1. Macula lutea
2. Xanthophyll pigments
3. Outer plexiform layer
4. Fovea centralis
Macula lutea and fovea centralis:
Rod photoreceptor cells are found within the _____, and rods become more prevalent continuing toward the periphery of the retina.
Macula lutea
Fovea centralis:
Near the fovea, the inner retinal layers become thinner and will disappear, such that at the most central region only the ___, ___, and ___ are present, with some of the plexiform layers.
Thus, a maximum level of light can reach the OS of primarily cone photoreceptors.
Blood vessels form a network of capillaries that are found at the periphery of the fovea centralis.
Outer nuclear layer, Inner segment, and outer segment
Fovea centralis:
Most of the visual input to the brain comes from the fovea.
Compared to the rest of the retina, the cones in the fovea centralis have a smaller diameter and can therefore be more densely packed in a _____ pattern.
Hexagonal pattern
Horizontal cells:
Horizontal cells, whose cell body is found in the INL, receive glutaminergic input from photoreceptors.
The dendrites and axon course parallel to the plane of the retina to nearby and distant photoreceptors.
Horizontal cells _____ the edge of a receptive field by _____ surrounding photoreceptor cells.
Sharpen
Inhibiting
**********Ganglion cells:
Ganglion cells are the output cells of the retina.
Soma of ganglion neurons are in the ganglion cell layer and their axons extend into the nuclear fiber layer.
GC _____ axons exit the retina at the optic nerve head, which is a weak region in the posterior pole of eye.
Unmyelinated
Optic n. is a central nerve. All cranial nerves except I and II are peripheral nerves.
Optic nerve head:
The axons of ganglion cells become myelinated within the optic nerve by oligodendrocytes.
Blood vessels exit or enter the retina at the optic nerve head and axons of ganglion cells exit the retina.
Oligodendrocytes
_____ is a systematic measurement of differential light sensitivity in the visual field by the detection of the presence of test targets on a defined background.
Visual field testing can be performed clinically with confrontational field testing keeping the subject's gaze fixed while presenting objects at various places in their visual field.
This is generally used to explore the extreme boundaries of the visual field.
This testing is important in the screening, diagnosing, and monitoring of various eye, retinal, optic nerve and brain disorders.
Perimetry
A person in a bright environment then moves to a dim environment.
- The retinas slowly become more sensitive to light as the person becomes accustomed to the dark.
- This decline in visual threshold is called dark adaptation.
- This response is maximal in about __ minutes.
30 minutes
-Light adaptation is the process that occurs when the eye is exposed to normal conditions for daylight vision, but it is used sometimes for the decreasing visual sensitivity which occurs when the eye remains in conditions of bright light.
-A person in a dim environment then moves to a bright environment.
- The light is intense and uncomfortable until the eyes adapt to the increased light and the visual threshold rises.
- Light adaptation occurs in less than a ___ minute period.
one
Accommodation:
The normal eye when viewing a distant object is unaccommodated and it is in focus.
A normal eye focuses an image of a distant object on its retina at the fovea 24 mm behind the cornea.
The focal length of the optics and the distance from the cornea to retina are matched, producing a state termed _____.
To bring closer objects into focus, the eye must increase its refractive power by accommodation.
emmetropia
Accommodation:
The ability to accommodate decreases with age as the lens loses its elasticity and hardens, which becomes noticeable in humans in their 40's.
Humans in their 50's generally lose accommodation termed _____.
Presbyopia
Testing visual acuity:
To determine visual acuity, distant vision is tested using a Snellen chart for individuals with normal vision.
Those individuals with abnormal vision, finger counting or movements can be used tested.
Abnormal vision is used to test human suffering from _____ and _____.
1. Snellen
2. age-related macular degeneration (ARMD) and retinitis pigmentosa (RP)
1. Nearsightness or _____ is the condition in which the refracting system (cornea, lens) is too powerful for the length of the eyeball.
2. The image of a distant object focuses in _____ of the retina (fovea) instead of at the retina.
3. The object will be in focus when the object is brought nearer to the eye using a _____ lens.
1. Myopia
2. Front
3. Biconcave
1. Farsightness or _____ is the condition in which the refracting system (cornea, lens) is too weak for the length of the eyeball.
2. This condition causes the image to appear at the fovea of the retina before it focuses (focuses behind the _____).
3. A _____ lens is used to correct this vision impairment.
1. Hyperopia
2. Fovea
3. Biconvex
1. _____ occurs when the curvature of the lens or cornea is greater in one axis.
2. If the refracting power of the cornea is greater in its vertical axis than its horizontal axis, the vertical rays will be refracted more than the horizontal rays producing a point source of light that looks like an _____.
1. Asitigmatism
2. ellipse
Astigmatism means that the cornea is _____ instead of spherical.
Most astigmatic corneas have two curves - a steeper curve and a flatter curve. This causes light to focus on more than one point in the eye, resulting in blurred vision at a distance or near.
Astigmatism often occurs along with nearsightedness or farsightedness.
oval
Fundoscopic Photography:
Retinal veins are typically somewhat _____ than the arterial branches
to which they run parallel.
The veins are darker and less reflective and lack a prominent streak of
reflected light that runs along the center of the arteries.
Larger
Age-related macular degeneration (ARMD) patients suffer from _____ vision loss (______) which is found in ageing population specifically involving a dysfunctional (age?) RPE.
ARMD is the leading causes of vision loss in the US of those 60 years and older; cataracts are the primary cause of blindness in the world.
Central vision loss (cones)
Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.
Macular degeneration occurs in dry (loss of pigment and formation of _____) and wet (new vessels) forms.
The RPE lose pigment granules and detach (debridement) from Bruch's membrane.
Drusen
1. _____ disease, an autosomal recessive hereditary disease, is a form of macular dystrophy that begins early in life and is the most common form of juvenile macular degeneration.
This disease occurs in 1 in 20,000 children over 6 years of age and over 25,000 Americans have this disease.
2. This disease is characterized by yellow flecks around the macula, called _____.
Cones are lost in the fovea of both eyes resulting in central vision loss.
1. Stargardt's disease
2. Fundus flavimaculatus
1. _____ patients suffer from _____ vision loss caused by defective ___ photoreceptors resulting from a dysfunctional or mutated protein involved in vision (opsin, peripherin - rds/peripherin).
39 genes and loci have been implicated in RP, but 50% of the RP cases have no known cause.
1. Retinitis pigmentosa (RP)
2. peripheral
3. Rod
1. _____ is the 2nd leading cause of blindness in the US.
2. Glaucoma is a diagnosis given to a group of ocular conditions that contribute to the loss of or damage to axons of _____ cells with a corresponding loss of vision (optic neuropathy).
3. Glaucoma is a disease of the _____ nerve, which transmits signals from the retina to the brain.
1. Glaucoma
2. Retinal ganglion
3. Optic
Glaucoma can be caused by blockage of aqueous humor outflow through the trabecular meshwork from the anterior chamber of the eye leading to increased intraocular pressure (IOP) above 25mm Hg.
This condition will result in _____ of the optic nerve head.
cupping
Age-related macular degeneration:
To date, therapy has not been developed that will affect restoration of sight, although some dietary therapies have been shown to slow the progression of the disease.
_____ of normal ___ have been attempted but have proven to be unsuccessful in restoration of sight in ARMD patients.
Transplants; RPE
Glaucoma:
Although studies suggest that more than 2 million Americans have glaucoma, it is estimated that about one million of them do not know it. Between 25-40% of optic nerve axons can be lost before vision loss is perceived.
This is in large part because the most common type of glaucoma in the US, _____ (90%), has no symptoms and only very subtle signs early in its course, whereas _____ glaucoma is painful and results in sudden vision loss and increased intraocular pressure.
1. Primary open angle glaucoma
2. Closed angle glaucoma
Diabetic retinopathy is the most common diabetic eye disorder and is a leading cause of blindness in middle-age adults. It is primarily caused by changes in and proliferation of retinal blood vessels.
In some people with diabetic retinopathy, blood vessels may swell and leak fluid (edema). In other people, abnormal new blood vessels grow onto the surface of the retina.
1. Blood vessels
Diabetic retinopathy:
Fragile, abnormal blood vessels (corkscrew appearance) can develop and leak blood into the center of the eye, blurring vision in diabetic retinas.
1. This is _____ retinopathy and is the 4th and most advanced stage of the diabetic retinopathy.
Fluid can leak into the center of the macula, the part of the eye where sharp, straight-ahead vision occurs.
2. The fluid makes the macula swell causing blurred vision. This condition is called _____.
It can occur at any stage of diabetic retinopathy, although it is more likely to occur as the disease progresses.
About half of the people with proliferative retinopathy also have macular edema.
1. proliferative retinopathy
2. macular edema
Optic nerve:
The orbital portion of the optic nerve is 3-4 mm in diameter and 20-30 mm long.
This portion is invested by sheaths derived from the meninges - dura mater, arachnoid, and the pia mater.
All three layers fuse and become continuous with the sclera at the lamina cribosa.
The dura extends to the _____, arachoid somewhat further, and the pia mater extends to the _____.
1. cranial cavity
2. optic chiasm
Optic atrophy:
Many diseases and disorders can lead to atrophy or damage to one or both optic nerves.
Optic atrophy can occur in people where the optic nerve or nerves did not develop properly.
It may also result from inflammation of the optic nerve or from glaucoma when the pressure inside the eye remains too high.
In unusual cases, poisons, vitamin deficiencies, or tumors may be responsible for damage to the optic nerve.
Most commonly, optic atrophy occurs without a known or proven cause.
5 Symptoms of optic atrophy include:
1. blurred vision
2. abnormal peripheral vision
3. abnormal color vision
4. poor constriction of the pupil in light
5. decreased brightness in one eye relative to the other
Atrophy of the optic nerve results in the color of the optic disc changing to pink, white, or gray.
Primary optic atrophy, possibly caused by _____ or _____, is associated with degeneration of the optic nerve, but does not produce papilledema.
Degeneration and atrophy of axons of the optic nerve is irreversible.
multiple sclerosis or neurosyphilis
Optic atrophy:
Secondary optic atrophy is associated with papilledema due to neuritis, glaucoma, or increased intracranial pressure.
To date, no treatment for optic atrophy has been developed, but early diagnosis is critical.
papilledema
1. _____ are blind spots in the visual fields.
In central _____ (same as 1st blank) loss of _____ vision is seen in _____ or _____ (without swelling of the optic disc).
These conditions are inflammation of the optic nerve either close to or behind the eye.
1. Scotomas
2. macular vision
3. Optic neuritis or retrobulbar neuritis
Papilledema, also termed _____, can be observed as a swelling of the optic nerve head.
This condition is usually bilateral, the nerve head is elevated and swollen but the pupillary response typically is normal.
Vision is usually not affected initially, but permanent vision loss can occur if the primary cause of the papilledema is left untreated.
1. Choked disc
Papilledema:
The swelling of the optic disk is characterized by _____ (increased blood), blurring of the disk margins, microhemorrhages, and engorgement of retinal veins.
Chronic papilledema may cause optic atrophy and visual loss.
Hyperemia
Physiology of vision:
Phototransduction is the process by which light, captured by a visual pigment in a photoreceptor cell outer segment, generates an electrical response.
1. Inside of the photoreceptor cell, normal levels of _____ keep the ___ channels open.
3. Thus, in the resting state the photoreceptor cell is _____.
4. Following stimulation by photons of light, cGMP is bound to and degraded by _____.
5. The cGMP cannot then bind to Na+ channels, thus making the cell _____.
1. cGMP
2. Na+
3. depolarized
4. G-proteins
5. Hyperpolarized
Physiology of vision:
1. Reduction in positive charge within outer segments makes its membrane potential more negative, thus it _____.
2. Due to an imbalance in electric charge in the OS, _____ ions are drawn from the terminal of the photoreceptor making it more _____.
4. This hyperpolarization of the photoreceptor terminal reduces the rate of _____ release.
5. Release of the neurotransmitter glutamate is highest in the _____, therefore glutamate signal is _____ to the level of photon absorption.
1. hyperpolarizes
2. positive ions
3. negative
4. Glutamate
5. dark
6. opposite
1. Rhodopsin belongs to the class of _____ receptors.
2. This molecule allows _____-vision, and is very sensitive to light.
3. When exposed to bright light, the pigment immediately _____, and it takes about __ minutes to regenerate fully in humans.
1. G-protein coupled receptors
2. night
3. bleaches
4. 30 minutes
1. The structure of rhodopsin consists of _____ that surround the photoreactive chromophore, ______.
3. Retinal, the chromophore portion of rhodopsin, is made in the retina from _____. (Humans cannot generate vitamin A).
4. Isomerization of 11-cis retinal into ______ by light induces a conformational change in the _____ that activates the associated G protein and triggers a second messenger cascade.
1. 7 transmembrane helices
2. 11-cis retinal
3. Vitamin A
4. all-trans-retinal
5. opsin
Photons of light strike the OS causing a conformational change of the photopigment opsin (11-cis retinal).
This change results in series of molecular changes that affects membrane potential changes leading to action potential at the level of the _____cell.
Ganglion cell
1. Phototransduction begins when photoexcited rhodopsin (R*) and the G protein _____ diffuse on the disk membrane, collide and then bind.
2. In this complex, __ catalyses the exchange of a GDP for a GTP on the _____ subunit and then the activated TAlpha* is _____.
5. This process repeats many times for each R*, and constitutes the first _____ step in the phototransduction cascade.
1. Transducin (T)
2. R*
3. TAlpha
4. released
5. amplifying
Phototransduction:
1. TAlpha* diffuses along the membrane surface eventually activating a single _____.
2. Hydrolysis of cGMP by _____ results in the _____ in the plasma membrane and the _____ photoresponse.
1. cGMP phosphodiesterase (PDE) subunit
2. TAlpha*-activated phosphodiesterase
3. closure of cationic channels
4. hyperpolarizing
Phototransduction:
In reverse, cGMP is synthesized from GTP by _____ which results in the _____.
1. Guanylate cyclase (GC)
2. reopening of cationic channels
********Role of RPE:
The retinal pigment epithelium is involved in the phagocytosis of the outer segment of photoreceptor cells.
This cell is also involved in the _____ cycle where it isomerizes all-trans retinol to _____.
1. Vitamin A cycle
2. 11-cis retinal
Role of RPE:
1. All-trans retinol is carried from the photoreceptor outer segment to the RPE by _____ and is converted in the RPE by _____ to _____.
4. This molecule is converted by _____ to _____, which is converted to _____ by _____.
11-cis retinal is carried to the OS by _____.
1. interstitial retinol-binding protein
2. lecithin retinol acyltransferase
3. all-trans retinyl ester
4. RPE65
5. 11-cis retinol
6. 11-cis retinol dehydrogenase
7. interstitial retinol-binding protein
Visual pathways:
The optic nerve consists of 1.2 million axons from the ganglion cells of the retina.
The axons course along the inner retina, pass through the lamina cribrosa of the sclera, and form the optic nerve.
The axons continue through the optic canal to form the optic chiasm.
The fibers of the nasal half of the retina _____ within the optic chiasm, while the temporal fibers _____.
1. Cross (contralateral)
2. remain ipsilateral
Visual pathways:
1. After passing through the optic chiasm, axons pass centrally in the optic tract and to the _____ and _____.
3. The LGN and medial geniculate nucleus are important relay nuclei within the _____.
4. From each LGN, axons pass ipsilateral via the optic radiation to the _____ (primary visual cortex) in the occipital lobe.
1. Lateral geniculate nucleus and superior colliculus
2. thalamus
3. Calcarine cortex
Optic radiation:
1. The _____ tract, or optic radiation, is a collection of axons from relay neurons in the 2. _____ nucleus of the thalamus carrying visual information to the visual cortex (striate cortex) along the 3. _____ fissure.
There is one such tract on each side of the brain.
A distinctive feature of the optic radiations is that they split into two parts on each side.
1. geniculocalcarine tract
2. lateral geniculate nucleus
3. calcarine fissure
Meyer's loop (Archambault's loop) are axons from the 1. _____ consisting of geniculocalcarine fibers that curve around the 2. _____.
These fibers reach forward into the temporal lobe before passing to the calcarine cortex.
Meyer's loop carries optic radiation fibers representing the 3. _____ quadrant of the 4. _____ visual field.
NOTE: images are projected INVERTED!
1. inferior retina*
2. inferior horn of the lateral ventricle
3. superior*
4. contralateral
A lesion in the temporal lobe damaging Meyer's loop causes a loss of vision in a _____ quadrant.
Superior quadrant
Meyer's loop:
The axons from the 1. _____ retina travel straight back to the occipital lobe in the 2. _____ limb of the 3. _____ to the visual cortex.
They carry information from the 4. _____ part of the visual field and, taking the shorter path, are less susceptible to damage.
1. superior retina
2. retrolenticular limb
3. internal capsule
4. inferior part
Axons of retinal ganglion cells in the optic tract also terminate in the _____ forming another retinotropic map.
The SC also receives fibers from the visual cortex.
The superior colliculus sends fibers to the spinal cord via _____ tracts which controls reflex movements of the ___, ___, and ___ in response to visual stimuli.
1. superior colliculus
2. tectospinal tracts
3. head, neck, and eyes
*****What is responsible for regenerating photoreactive chromophore 11-cis retinal
*****Retinal pigment epithelium
Several closely related opsins in cones, called _____, exist that differ only in a few amino acids and in the wavelengths of light that they absorb most strongly.
These pigments are found in the different types of the cone photoreceptor cells of the retina and are the basis of color vision.
photopsins
Under dark conditions:
1. polarization?
2. Glutamate release?
3. cGMP/GTP
Under light conditions:
Dark:
1. Depolarized
2. Glutamate is released
3. cGMP
Light:
1. Hyperpolarized
2. Glutamate decreased
4. GTP
1. The Temporal visual field is picked up by what side of the eye?
2. This vision travels to what side of the visual cortex?
3. The Nasal visual field is picked up by what side of the eye?
4. This vision travels to what side of the visual cortex?
1. nasal side
2. contralateral
3. temporal side
4. ipsilateral
1. Temporal visual field goes to _____ visual cortex
2. Nasal visual field goes to _____ visual cortex
1. contralateral
2. ipsilateral
If you damage the right Meyer's loop, you loose vision where?
right superior nasal field
left superior temporal field
Lesions of visual pathway:
A lesion at the optic nerve head affecting the central region will result in vision loss at the 1. _____.
A lesion of the complete optic nerve results in complete vision loss in the respective eye.
Lesion of the optic tracts results in vision loss in the ipsilateral nasal field and contralateral temporal field, termed 2. _____
1. macula
2. homonymous hemianopsia
Meyer's loop carries optic radiation fibers representing the upper part of the contralateral field, thus temporal lobe lesions can produce a visual field deficit involving the contralateral superior quadrant.
This visual field defect is called _____.
Superior quadrantanopsia
A lesion of the right optic tract represents the loss of the left hemifield. Both eyes will be blind to anything on the left side of the world, assuming the eyes are pointed straight ahead
This is called left _____
Homonymous hemianopsia
If the right Meyer's loop has been cut, vision will be lost in the superior visual world, but only in the left hemifield.
If the right parietal portion of the optic radiations were cut it would affect the _____ visual world in the left hemifield.
Lower
A complete hemifield is not lost following a lesion in the cortex.
A notched hemifield results which is called _____.
macular sparing
Occlusion of the ophthalmic artery can cause blindness in the respective eye.
Occlusion of the posterior cerebral artery can cause 1. _____.
The LGN is supplied by a branch of the posterior cerebral artery, 2. _____ artery.
1. homonymous hemianopsia
2. thalamogeniculate a.
Edinger-Westphal nucleus sends parasympathetic neurons within the oculomotor nerve to terminate in the _____ ganglion.
Postganglionic neurons in the _____ ganglion project to the iris sphincter muscle.
This loop of neurons is responsible for the pupillary light reflex which results in the constriction of the pupil in response to light.
Thus, light shone on the retina of one eye causes both pupils to constrict.
1. ciliary
What nuclei communicate with the Edinger-Westphal nuclei?
Pretectal nuclei
all three taste sensory components
of tongue (CN VII, IX, and X) synapse in the _____
Solitary nucleus
What innervates the epiglottis?
Vagus CN X
All the taste sensory components
of the nerves VII, IX and X synapse in the ipsilateral solitary nucleus and then send projections to the _____ of the thalamus and then on to the cortex (e.g., insula and postcentral gyrus)
1. ipsilateral
2. Ventral Posterior Medial - VPM nucleus
Brodmann area 43
Gustatory cortex (taste?)
Damage to the cribriform plate can result in _____ (loss of the sense of smell) due to damage of olfactory nerve fibers
Anosmia
In contrast to anosmia, a seizure or lesion in the primary olfactory cortex or _____ can result in olfactory hallucinations leading to the perception of unpleasant orders.
uncus
Clinical causes of anosmia:
-Nasal Infection is the most common cause of anosmia, including the common cold
-Damage to the cribriform plate due to head trauma resulting in damage to olfactory nerves, bulbs or tracts.
-1. Tumors in the _____ above the cribriform plates, in other words, near the base of the frontal lobe (e.g., olfactory groove meningiomas) can lead to compression or invasion injuries of the olfactory bulbs or tracts
2. Note: Anosmia often goes unreported unless _____
1. Dura lining
2. Bilateral
Classification of sensory receptors based on location:
1. found near the body surface
respond to stimuli arising outside the body
sensitive to touch, pressure, pain, temperature
2. found in internal viscera and blood vessels
respond to stimuli arising within the body
sensitive to chemical changes, stretch, temperature changes
3. located in skeletal muscles, tendons, joints, ligaments, connective tissue
coverings of bones and muscles
respond to degree of stretch of organs they occupy
constantly "advise" the brain of one's movements
1. Exteroceptors
2. Interoceptors
3. Proprioceptors
SOMATOSENSORY SYSTEM Sensory Receptors Based on Stimulus Type:
1. sensitive to stimuli that deform their cell membranes, e.g., touch, pressure, vibration, stretch
2. sensitive to changes in temperature; very active when temperature is changing but quickly adapt to stable temperature
3. sensitive to potentially damaging stimuli that result in pain, e.g., extremes of temperature, excessive pressure, inflammatory chemicals
1. Mechanoreceptors
2. Thermoreceptors
3. Nociceptors
SOMATOSENSORY SYSTEM Sensory Receptors Based on Structure
1. free nerve endings, Merkel discs, hair follicle receptors
respond to temperature and painful stimuli, tissue movements caused by pressure, itch
2. Meissner's corpuscles, Pacinian corpuscles, Ruffini endings, muscle spindles, Golgi tendon organs, joint kinesthetic receptors
respond to light and deep pressure, discriminative touch, low and high frequency vibration, muscle stretch & length, (tendon stretch & tension)
1. Unencapsulated nerve endings
2. Encapsulated nerve endings
ANTEROLATERAL SYSTEM
1. Lateral Spinothalamic Tract senses 2:
2. Anterior Spinothalamic Tract senses 2:
DORSAL COLUMN-MEDIAL LEMNISCAL PATHWAY senses 7:
1. Pain & temperature
2. Light (crude) touch & pressure
3. Pressure
Discriminative touch (Stereognosis - identify object in hand with eyes closed, 2-point discrimination, complex tactile discrimination - write on skin)
vibratory sense
proprioception
2nd order sensory neurons synapse in the thalamus at:
1. Coming from body
2. Coming from head
1. Ventral Posterior Lateral - VPL
2. Ventral Posterior Medial - VPM
SPINOCEREBELLAR PATHWAYS
1. PosteriorSpinocerebellar Tract
carries sensations from _____ proprioceptors for maintenance of posture and coordination of limb movements
2. Anterior Spinocerebellar Tract
carries sensation from _____ proprioceptors for maintenance of posture and coordination of limb movements
1. Trunk and lower limb
2. Trunk, upper, and lower limb
_____ Tract
Responsible for the relay and processing of somatosensory information from the head, especially the face, the oral cavity, the nasal cavity, the teeth, and the cornea
Trigeminothalamic Tract
1. Rexed Lamina II - also known as _____
2. What is released here?
3. Contains 2nd order neurons for what pathway?
4. Rexed Lamina VII - contains the _____
5. Contains 2nd order neurons for what pathway?
1. Substantia gelatinosa
2. Substance P (for pain sensation)
3. Spinothalamic tract
4. Dorsal nucleus of Clarke
5. Spinocerebellar tract
Brodmann's areas 3, 1, 2
Primary somatosensory cortex (postcentral gyrus)
Spinocerebellar tracts
1. Ascends uncrossed unconditionally
2. crosses most of the time in spinal cord and then crosses back to original side in the cerebellum
3. Lesion of this tract would cause symptoms
1. Posterior spinocerebellar tract
2. Anterior spinocerebellar tract
3. ipsilaterally
1. Sensory nerves
2. Motor nerves
3. Mixed nerves
1. CN 1, 2, 8
2. CN 3, 4, 6, 12
3. CN 5, 7, 9, 10
Gracile and cuneate nuclei are ___ order neurons of the Dorsal column pathway
2nd order
Internal arcuate fibers are the axons of ___ order neurons of _____
1. 2nd order
2. Gracile and cuneate nuclei
1. Spinal trigeminal nucleus contains ___ order neurons.
2. Spinal trigeminal nucleus and tract extends from superior colliculus to ____?
1. 2nd order
2. Level of C4 of spinal cord
Broca's area is located on what side of the cortex?
Left
The only difference between the motor and sensory homunculus is?
The motor homunculus does not contain the genitals
The spinothalamic tract crosses the spinal cord in the?
Ventral white commissure
UNCONSCIOUS PROPRIOCEPTIVE STIMULI
SYNAPSE IN THE CEREBELLAR CORTEX
ON THE _____ AS THE ORIGINAL STIMULI
Same side
Romberg Sign
Inability to maintain a steady posture with the feet close together, after the eyes are closed, because of loss of proprioceptive input ("sensory ataxia")
Results from damage to dorsal column, as seen in _____, a form of tertiary neurosyphilis
Tabes dorsalis
Trigeminal System: Pathway for Pain & Temperature
1. Receptors -> _____ (___-order neuron) -> central processes form _____, enter pons and divide into descending and ascending branches...

3. Descending branch form the _____ tract -> _____ (___-order neuron) -> CROSS to opposite side -> _____ -> _____ nucleus of thalamus (3rd-order neuron) -> posterior limb of internal capsule -> _____
1. Trigeminal ganglion (1st order neuron)
2. Sensory root of CN V
3. spinal trigeminal tract -> nucleus (2nd order neuron)
4. Trigeminothalamic tract
5. Ventral Posterior Medial - VPM
6. Postcentral gyrus
Trigeminal System: Pathway for Discriminative Touch, Conscious Proprioception, and Vibratory Sense:
Receptors -> _____ (___-order neuron) -> central processes form sensory root of CN V, enter pons and divide into descending and ascending branches...

Ascending branch -> _____ (___-order neuron) -> CROSS to opposite side -> trigeminothalamic tract -> _____ nucleus of thalamus (3rd-order neuron) -> posterior limb of internal capsule -> postcentral gyrus
1. Trigeminal gangion; 1st order neuron
2. . Principal sensory nucleus of CN V; 2nd order neuron
3. Ventral Posterior Medial - VPM
Trigeminal System: Pathway for Unconscious Proprioception:
Receptors/proprioceptors -> _____ (___ order neuron) -> axons form _____ -> BILATERAL PROJECTIONS -> _____, _____, _____
1. Mesencephalic nucleus of CN V; 1st order neuron
2. Mesencephalic tract of CN V
3. Cerebellum
Reticular Formation
Motor Nucleus of CN V
Hemisection of Spinal Cord (Brown-Séquard Syndrome):
CAUSES: trauma, vascular injury
MANIFESTATIONS - below the lesion
1. _____ loss of discriminative touch, vibratory sense, proprioception - due to involvement of the dorsal column-medial lemniscus pathway
2. _____ loss of pain & temperature sense and light touch & pressure - due to involvement of the lateral and ventral spinothalamic tracts
3. spastic paralysis - due to involvement of the corticospinal tracts
Note: The spinocerebellar tracts are also injured in this type of lesion but can not be evaluated because the involved limb is paralyzed!
1. Ipsilateral
2. contralateral
3. ipsilateral
Lateral Medullary (Wallenberg, PICA) Syndrome:
CAUSE: occlusion of the vertebral artery or the posterior inferior cerebellar artery
MANIFESTATIONS - "Alternating Hemianesthesia"
1. _____ loss of _____ sense in the face - due to involvement of the spinal trigeminal nucleus and tract
2. _____ loss of _____ sense in the body - due to involvement of the anterolateral system
3. _____ - due to involvement of the dorsal spinocerebellar tract, inferior cerebellar peduncle, or cerebellum
4. Dysphagia and dysarthria - due to involvement of the _____ and consequent paralysis of the _____ palatal and laryngeal muscles
5. Vertigo, nausea, vomiting, and nystagmus - due to involvement of the _____ vestibular nuclei
6. _____ Horner's syndrome - due to involvement of the descending sympathetic fibers from the hypothalamus
1. Ipsilateral; pain and temperature sense
2. Contralateral; pain and temperature sense
3. Ipsilateral ataxia
4. nucleus ambiguus; ipsilateral
5. ipsilateral
6. Ipsilateral
1. Dorsal/posterior spinocerebellar tract fibers enter cerebellum at?
2. Ventral/anterior spinocerebellar tract fibers that remain ipsilateral enter cerebellum at?
3. Ventral/anterior spinocerebellar tract fibers that cross and then cross back enter cerebellum at?
1. Inferior cerebellar peduncle
2. Superior cerebellar peduncle
3. Middle cerebellar peduncle
Interomedial lateral cell column extends from T1-L2 and contains?
Descending sympathetic fibers from the hypothalamus
4 Roles of Limbic system
1. Homeostasis
2. Olfaction
3. Memory
4. Emotion
"HOME"
Three telencephalic structures in limbic system:
1. Limbic association cortex & cingulum
2. Hippocampus and its pathway (fornix)
3. Amygdala and its pathway (stria terminalis)
4 Gyri/Limbic association cortices:
1. Cingulate gyrus
2. Parahippocampal gyrus
3. Medial orbitofrontal gyri
4. Gyri of the temporal pole
1. Olfactory projection area (near _____ in temporal lobe) receives olfactory information (through lateral olfactory stria)
- 2. Olfactory projection area includes the _____, _____ and _____
- Pyriform cortex -> thalamus -> frontal lobe
-Pathway associated with _____
1. Uncus
2. Pyriform cortex, entorhinal cortex, and amygdala
3. Conscious discrimination of odors
Three effector systems for the behavioral expression of emotion:
- Somatic motor system - behavioral signs of emotion
- 1. Endocrine system - corticomedial division of amygdala projects to _____, which in turn, projects to _____
- 2. Autonomic system (primarily sympathetic) - _____ nucleus -> brainstem (dorsal motor nucleus of Vagus nerve) - via_____ pathway; also amygdala projections to _____
1. VMN; arcuate nucleus
2. Central amygdaloid nucleus
Ventral amygdalofugal pathway
Paraventricular Nucelus - PVN
Role of the frontal, cingulate and parahippocampal cortices:
Orbitofrontal 3:
Cortex:
1. Dilation of pupils, salivation, involved in arousal
2. Important for keeping inappropriate behaviors in check (example of Phineas Gage - lesion of ventromedial cortex)
Hippocampus:
1. Important in _____
The example of patient "H.M."
- 2. After having bilateral temporal lobectomy, _____ was impaired, but _____ was spared. (Forster will elaborate)
3. Main input is from _____, which in turn, receives input from association cortices:
- 4. _____, _____, _____ -> entorhinal cortex -> _____ -> hippocampus proper (CA3).
- 5. Projects, via the fornix, to the _____
1. memory
2. long term memory; short term memory
3. entorhinal cortex
4. Frontal, parieto-occipital, temporal cortices
Dentate gyrus
5. Mammillary bodies
Hypothalamus:
- Regulates autonomic output
- A coordinating center that integrates various (peripheral) inputs into appropriate set of autonomic/somatic responses
-Therefore, hypothalamus coordinates the _____
Peripheral expression of emotions
Trace Papez circuit
Slide 19
Amygdaloid complex Three divisions:
-Basolateral
largest component in humans
1. connects with cortical association areas, via _____; involved in _____
-Corticomedial
2. connects to _____ hypothalamus via _____; also connects with _____ structures; involved in _____
-Central nucleus
3. connects with _____ and _____ centers in hypothalamus; regulates _____ and _____ function
1. Dorsal medial nucleus of thalamus; attaching emotional significance to a stimulus
2. VMN of hypothalamus via stria terminalis
olfactory structures
appetitive behavior
3. brainstem and autonomic
visceral and Cardiovascular function
Interconnections of the amygdala:
1. Basolateral nucleus of amygdala: receives sensory input and relays this to the _____ of the amygdala
2. Stimulation of central nucleus leads to increased __, __ and _____ via outputs to
3. _____ and _____
Thus, heart rate, sweating, gastric secretion, and other autonomic responses are influenced by strong emotions.
4. Connections to cortical association areas (cingulate, orbitofrontal cortices) - via _____
5. Important for _____
1. Central nucleus
2. HR, BP, and respiration
3. Lateral hypothalamus and brainstem
4. Uncinate fasciculus
5. Arousal (damage causes flat affect/unreactive response to things that should arouse you)
Interconnections of the Amygdala (cont'd):
1. Amygdala projects (via _____) to hypothalamus
- important for neuroendocrinological changes in response to emotions
-Projection from _____ n. to ___ may carry olfactory information that alters _____
-Projection to _____ can influence neuroendocrine responses to fearful and/or stressful responses
-Depression influences immune system (via hypothalamic regulation)
1. stria terminalis
2. corticomedial nucleus to VMN; appetite
3. Paraventricular nucleus - PVN
Ventral amygdalofugal pathway:
Pathway from amygdala to forebrain
- 1. Connection to _____ and _____
- 2. Involved in _____ and _____
Pathway from amygdala to hypothalamus
- Involved in _____ and _____
Pathway from amygdala to brainstem
- Connects to 4:
5. NOTE: connections between amygdala, hypothalamus and brainstem travel in _____
1. Nucleus basalis and septal nuclei
2. Cognition and motivation
3. Homeostatic function and behavioral arousal
4. Periaquaductal gray (pain modulation), nucleus of the vagus, reticular formation, parabrachial nucleus
5. Medial forebrain bundle
Amygdala Connections with the hippocampus are
Important for _____
Fear memory
Amygdala:
1. _____ lesions lead to "tameness", psychic blindness, hyperorality, loss of sexual inhibition
- 2. _____ syndrome
3. Electrical stimulation of the amygdala leads to feelings of _____ and _____
- 4. Seizure activity in the amygdala and surrounding cortex results in _____ and _____
Amygdala is involved in the "unconscious" response to emotional stimuli (i.e., distinguishing happy face from angry face)
- Lesions of the amygdala may foster a "disconnect" between visual stimuli and affective responses
Also involved in learned emotional responses (conditioned responses), both negative (fear) and positive (reward)
5. _____ complex of amygdala
1. Bilateral temporal lobe lesions
2. Kluver-Bucy syndrome
3. Fear and apprehension
4. Panic and fear
5. Basolateral complex
Anatomical regions of importance as it relates to the theories of emotion:
1. Peripheral (autonomic) component involves the _____
2. Central component (conscious and unconscious) involves the _____ cerebral cortex (cingulate and prefrontal)
Amygdala
1. Hypothalamus
2. Cerebral cortex (cingulate and prefrontal)
Temporal lobe seizures:
Can result in symptoms characteristic of limbic system involvement 3:
1. "dreamy state"
2. Olfactory/auditory hallucinations
3. Memory loss
"Uncinate fits" - seizures from the uncal part of the temporal lobe results in _____.
"dreamy state"
The _____, not the hippocampus, coordinates the activity of the hypothalamus with cortical areas
Amygdala
Neuroendocrine and Limbic system association is part of what division of amygdala?
Corticomedial
How does amygdala communicate with hypothalamus and brainstem?
Medial forebrain bundle
Medial hypothalamus is separated from lateral component of the hypothalamus by the _____
fornix
Major divisions of the hypothalamus (lateral -> medial)
1. Lateral function
2. Medial function
3. Periventricular function (most medial)
1. - Relay station (MFB: mediates connections between brain stem, hypothalamus & cerebral cortex)
- Hunger center
2. Site of input from limbic system
3. Important in Neuroendocrine regulation
5 Ventral (under) view structures surrounding the hypothalamus:
1. Optic chiasm
2. Infundibulum (and surrounding tuber cinereum)
3. Position of the pituitary
4. Mammillary bodies
6. Circle of Willis
6 Mid-sagittal view structures surrounding the hypothalamus:
1. 3rd ventricle
- Supraoptic recess
- Infundibular recess
- Lamina terminalis
2. Pituitary gland
3. Mammillary bodies
4. Anterior commissure
5. Posterior commissure
6. Hypothalamic sulcus - Dorsal (top) boundary
5 Coronal view structures surrounding the hypothalamus:
1. 3rd ventricle
2. Periventricular area
3. Mammillothalamic tract
4. Fornix
5. Median eminence
Blood supply to the pituitary:
Superior hypophyseal artery (from internal carotid) gives rise to capillary plexus in _____, which gives rise to another capillary plexus in the _____
Median eminence
pituitary
(S16) Boundaries of the hypothalamus:
1. Anterior
2. Dorsal (top)
3. Posterior
4. Ventral (bottom)
1. anterior commissure to optic chiasm
2. Anterior commissure to posterior commissure/rostral superior colliculi
3. posterior/inferior mammillary bodies -> posterior commissure/rostral superior colliculus
4. air/bone
Anterior-posterior organization of the hypothalamus
1. 4 Anterior (lamina terminalis -> chiasm) contents:
2. 3 Middle (tuberal) (chiasm -> mammilary bodies) nuceli:
3. Posterior (mammilary bodies) nuclei
1. Medial preoptic area (MPOA) - thermoregulation
Paraventricular n.
Suprachiasmatic nucleus (SCN)
Supraoptic nucleus (SON)
2. Dorsomedial n.
Ventromedial n. - satiety center
Arcuate
3. Mammillary nuclei
*Also involved in thermoregulation
Hypothalamic inputs (afferents)
1. Ascending inputs
Noradrenergic
Serotonergic
Cholinergic
2. Peptidergic signals
3. State of internal milieu
thermoreceptors
osmoreceptors
glucoreceptors
4. Nociceptive input: (from dorsal horn of spinal cord)
5. Hippocampus, Amygdala, Septum
Hypothalamic afferents pathways:
1. Medial forebrain bundle - From 4:
2. Fornix - from:
3. *****Stria terminalis - from:
4. Ventral noradrenergic bundle - from:
5. Dorsal noradrenergic bundle - from:
6. Retinohypothalamic pathway - from:
1. septal nucleus, striatum, thalamus, parolfactory area
2. hippocampus to hypothalamus (primarily mammillary bodies)
3. ****corticomedial amygdala (connects amygdala in limbic system with hypothalamus)****
4. Solitary nucleus (which receives viscerosensory information from CN IX and X)
5. Locus ceruleus to dorsal hypothalamus
6. retina to Suprachiasmatic nucleus (SCN)
Hypothalamic efferents:
1. Hypothalamo-hypophyseal tract (from what to what)?
Mamillotegmental tract (found within the MFB)
Mamillothalamic tract
Hypothalamus to autonomic nuclei in brain stem and spinal cord
- 2. Mainly from 4:
1. Supraoptic nucleus & Paraventricular nucleus to posterior pituitary
2. The Paraventricular nucleus (PVN)
lateral hypothalamic area
Dorsomedial hypothalamus (DMH)
posterior hypothalamic area
The Hypothalamus and Neuroendocrine function:
1. _____ neurosecretory system - Large diameter neurons whose terminals release peptide hormones directly into capillaries of the systemic circulation (posterior pituitary)
2. _____ neurosecretory system - Small diameter neurons that release factors (neurotransmitters and/or peptide hormones) into portal circulation (anterior pituitary)
1. Magnocellular neurosecretory system
2. Parvocellular neurosecretory system
Magnocellular neurosecretory system:
1. Regulate the release of _____
2. Supraoptic nucleus (SON) & Paraventricular nucleus (PVN) - both nuclei have distinct _____ and _____ producing neurons
3. Axons of SON and PVN extend down through the infundibulum* and terminate on fenestrated capillaries in _____ lobe of pituitary
1. posterior pituitary (neurohypophysis) hormones (ADH)
2. oxytocin and vasopressin (ArginineVasoPressin = AVP)
3. posterior lobe
Damage to the infundibulum may cause _____
Diabetes insipidus
Parvocellular neurosecretory system:
1. Regulates the release of _____
Hypothalamic neurons release factors into pituitary portal circulation (located in the median eminence), which then act on epithelial secretory cells in the anterior pituitary to modulate the release of anterior pituitary hormones.
1. anterior pituitary (adenohypophysis) hormones
Hypothalamic inputs to the median eminence:
1. Primarily in the periventricular area and consist of 3:
Can also have extrahypothalamic source of projections to the median eminence (ex. Septal nuclei)
1. Arcuate nucleus
Medial preoptic area - MPOA
Medial "parvocellular" component of the Paraventricular nucleus - PVN
The H-P-A axis:
PARAventricular nucleus - PVN receives input from various nuclei to provide input regarding:
- 1. the state of the autonomic system via _____ and _____
- State of arousal
- 2. pain input from?
- environment (via visual cues) from?
4. Based upon this input, the PVN (_____ component) may be stimulated to release Corticotropin releasing hormone CRH -> corticotrophs -> increase ACTH -> stimulate the synthesis and release of _____ from _____
1. Nucleus of the solitary tract (inputs from CN IX & X) and Locus Ceruleus
2. Periaqueductal grey
3. Suprachiasmatic nucleus (circadian rhythms)
4. Parvocellular
5. Glucocorticoids from adrenal cortex
HPA Disease? Can happen with cessation of chronic glucocorticoid therapy; pituitary apoplexy (hemorrhage)
- Symptoms include malaise, lethargy, weight loss, muscle weakness, and can result in hypotension and low serum sodium levels
Addison's disease (hypocortisolemia)
HPA Disease? May be attributed to a ACTH producing pituitary adenoma
- Alternatively, it may due to a adrenal tumor
- Symptoms include specific patterns of weight gain (moon face, fat deposition on neck and upper back), weakness of muscles in upper arms and legs.
Cushing's disease (hypercortisolemia)
H-P-T Axis:
_____ neurons produces TRH -> TSH -> increase T4 and T3 production in the thyroid gland
- Regulation of TRH release can be from neuronal inputs (autonomic system, SCN) or non-hypothalamic inputs (via cytokines, IL-1, TNFa *)
PERIventricular neurons
HPT Axis clinical conditions:
- Mainly associated with dysfunction of the end organ (thyroid gland)
- Hypothyroidism = low blood levels of T3/T4
- 1. Hyperthyroidism (_____ Disease) = high blood levels of T3/T4
Rarely, pituitary apoplexy may impair thyroid function by dysregulating TRH and TSH release
1. Grave's
2. apoplexy
H-P-G Axis:
1. GnRH producing cells include neurons of the _____ (females), _____ (males), and _____ nucleus (both)
GnRH stimulates the release of FSH and LH, which in turn stimulate sex steroid production and release at the level of the gonad
1. Medial Preoptic area - POA
2. Medial basal hypothalamus
3. Arcuate nucleus
1. The posterior pituitary blood supply comes from the:
2. The anterior pituitary blood supply comes from the:
1. Inferior hypophyseal a.
2. Superior hypophyseal a.
1. Arcuate nuclei release their NT where?
2. Paraventricular and supraoptic nuclei tracts go where?
1. blood supply (plexus) to anterior pituitary
2. thru the infundibulum directly to the posterior pituitary
Growth Hormone, Prolactin and b-Endorphin:
1. Neurons of the _____ nucleus produce:
- GHRH (that will stimulate GH release)
- *****2. DA which suppresses _____ release (through the _____ system, or additionally, through the _____ system)
3. (NOT important) Prolactin release is stimulated by the _____ nucleus via the release of Thyrotrophin Releasing Hormone - TRH and Vasoactive Intestinal Peptide - VIP
- 4. b-endorphin (through cleavage of its precursor, POMC) projects to _____ to promote analgesia
5. Inputs to the arcuate nucleus include:
1. Arcuate
2. Prolactin - PRL; Tuberoinfundibular dopamine system - TIDA; tuberohypophyseal system
3. Paraventricular nucleus - PVN
4. Periaqueductal grey
5. Noradrenergic, DAergic, serotonergic, and enkephalinergic
H-P-Gonadal Clinical Syndromes:
Acromegaly (GH excess); Dwarfism (GH deficiency)
Giantism (also GH excess)
Hyperprolactinemia (dysfunction of _____)
Pituitary tumor - causes?
1. Tuberoinfundibular Dopamine neurons
2. Visual impairment - Bitemporal hemianopsia (tunnel vision)
Thermoregulation:
1. Involves the _____ (part of the anterior hypothalamus) and posterior hypothalamus
2. The _____ projects to these regions (circadian regulation of body temp. - high in evening, lower at dawn)
3. In situations that lead to infections, cytokines can influence the hypothalamus at the level of the _____ (in particular the OVLT), where the production of prostaglandins are stimulated.
4. The anterior hypothalamus that is involved in thermoregulation is rich in _____ receptors, and may be the anatomical substrate for the menopausal "hot flush".
1. Preoptic area - POA
2. Suprachiasmatic nucleus - SCN
3. Circumventricular organs
4. Estrogen
Hypothalamic Regulatory Systems:
Regulation of Circadian Rhythms
"natural rhythm" of about 24 - 25hrs
Importance of Suprachiasmatic nucleus - SCN
Zeitgebers (time keepers) - stimuli that modify the endogenous cycle
Most prominent zeitgeber is light (_____ pathway)
Other zeitgebers include activity and sleep
Pineal melatonin & the Suprachiasmatic nucleus - SCN - has seemingly greater impact on seasonal breeders; in humans, may influence "jet lag"
1. retino-hypothalamic pathway
Food Intake:
Satiety center
- 1. Short term satiety cues exist even in _____ animals
- 2. Vagal afferents to the _____ nucleus
3. More long term satiety cues are signaled by _____ (produced by fat cells)
4. Regulation of food intake is regulated by peptide neurotransmitters such as ___ (produced in the arcuate nucleus and project to the PVN)
1. Decerebrate
2. Solitary nucleus
3. Leptin
4. NPY
Somatostatin released by the anterior Paraventricular nucleus inhibits what?
Growth hormone release from the pituitary
The epithalamus consists of what 2 things?
Epithalamus
• Pineal gland
• Habenular Nuclei
- Connect with the limbic system
Function of Thalamus
• Complicated collection of nerve cells centrally
located in brain and interconnected
• Sensory information except _____ converge in
thalamus and integrated by interconnections
• Thalamus and cerebral cortex closely linked
anatomically and functionally
• Nuclei are organized as principal nuclear masses
- Anterior, medial and lateral
- Nuclear masses separated by the _____
• Contains intralaminar nuclei
1. Smell
2. Internal medullary lamina
1. What thalamic nucleus receives 2nd order neurons from spinal sensory nerves?
2. Third order neuron has cell body in thalamus
and sends a projection axon to the _____
1. Ventral posterioLATERAL nucleus of thalamus
2. post central gyrus or somatosensory cortex
1. First order cranial sensory neurons leave peripheral area of the head, has cell bodies in ___,
travels to the ____ where it synapses with the
2nd order neuron cell body in trigeminal
sensory nucleus, nucleus of the spinal tract of
the trigeminal or mesencephalic nucleus
3. Second order neuron immediately decussates
or crosses over to opposite side and ascends
to _____ nucleus of thalamus
4. Third order neuron has cell body in thalamus
and sends a projection axon to the _____
1. trigeminal ganglion
2. pons
3. ventral posterioMEDIAL nucleus of thalamus
4. postcentral gyrus or somatosensory cortex
1. What is hemiballismus
2. Treatment
3. Injury is usually to?
-Decreased inhibition (indirect pathway)
1. Contralateral flinging of one or both limbs
2. Dopamine antagonist
3. Subthalamic nucleus
Habenular Nuclei of Epithalamus connects with?
limbic system
Subthalamus is comprised of what 2 things?
1. subthalamic nucleus
2. zona incerta
Subthalamic Nucleus
1. Connects with _____ and _____
2. Involved in _____
3. Lesion leads to _____
1. Globus pallidus and substantia nigra
2. movement
3. hemiballismus
1. Thalamic _____ receive information from reticular formation and ascending sensory systems and is responsible for activation of cerebral cortex activity,
2. Leads to levels of _____ and _____
1. Intralaminar
2. consciousness and alertness
Which thalamic nuclear group is involved in the control of instinctive drives and emotional aspects of behaviour and in memory
Anterior nuclear group
Which thalamic nuclear group's Ventroanterior and ventrolateral form part of basal nuclei
and affect voluntary movements
Lateral nuclear group
Which thalamic nuclear group is thought to control mood and emotions
Medial nuclear group
Anterior relay nuclei:
1. Input
2. Output
3. Function
1. Mamillothalamic tract, mamillary body of the hypothalamus
2. Cingulate gyrus
3. Emotional tone and mechanisms of recent memory
Lateral dorsal relay nuclei:
1. Input
2. Output
3. Function
1. Input-Hippocampus
2. Output-Cingulate gyrus
3. Function-Part of the limbic system
Ventral anterior relay nuclei:
1. Input
2. Output
3. Function
1. Input-Ipsilateral basal ganglia, Substantia nigra
2. Output-Premotor and supplementary motor cortices
3. Function-Normal movement and mediation of
abnormal movement in basal ganglia disorders
Ventral lateral relay nuclei:
1. Input
2. Output
3. Function
1. Input-Ipsilateral globus pallidus and substantia nigra
and contralateral dentate nucleus of the cerebellum
2. Output- Motor areas of frontal lobe, especially
primary motor cortex of precentral gyrus
3. Function-Influences motor activity of cortex
Ventral posteriomedial relay nuclei:
1. Input
2. Output
3. Function
1. Input-Trigeminothalamic tract, nucleus solitarius,
vestibular nuclei
2. Output-Primary somatic sensory (areas 3,1, and 2)
cortex
3. Function-Relays common sensations to consciousness
Ventral posteriolateral relay nuclei:
1. Input
2. Output
3. Function
1. Input-Spinothalamic tract and medial lemniscus,
nucleus solitarius, vestibular nuclei
2. Output-Primary somatic sensory (areas 3,1, and 2)
cortex
3. Function-Relays common sensations to consciousness
Intralaminar (IL)-Centromedian and Parafscicular relay nuclei:
1. Input
2. Output
3. Function
1. Input-Reticular formation, spinothalamic and
trigeminothalamic tracts
2. Output-Cerebral cortex, caudate nucleus and putamen
3. Function- Activate cerebral cortical mantle, lesions of
IL reduce perception of pain and level of
consciousness
Midline relay nuclei:
1. Input
2. Output
3. Function
1. Input-Basal ganglia and limbic system
2. Output-Cerebral cortex, basal ganglia and limbic
system
3. Function- Form interthalamic adhesion, cover
ventricular surface
Reticular relay nuclei:
1. Input
2. Output
3. Function
1. Input- Cerebral cortex and thalamic projection
neurons
2. Output-Inhibitory (GABA) neurons to other thalamic
nuclei
3. Function-Regulatory input to the thalamus
Medial geniculate nucleus relay nuclei:
1. Input
2. Output
3. Function
1. Input-Inferior colliculus, lateral lemniscus from both
ears
2. Output- Auditory cortex in temporal lobe via retroand
sub-lenticular part of internal capsule and auditory
radiation
3. Function- Hearing
Lateral geniculate nucleus relay nuclei:
1. Input
2. Output
3. Function
1. Input-Optic tract
2. Output- Primary visual cortex in occipital lobe via
retrolenticular part of internal capsule and optic
radiation
3. Function-Vision
Dorsomedial association nuclei:
1. Input
2. Output
3. Function
1. Input-Prefrontal cortex, olfactory and limbic system
2. Output-Prefrontal cortex
3. Function-Control of mood and emotions
Lateral posterior association nuclei:
1. Input
2. Output
3. Function
1. Input- Sensory association cortex of parietal lobe
2. Output- Sensory association cortex of parietal lobe
3. Function-Still being investigated
Pulvinar association nuclei:
1. Input
2. Output
3. Function
1. Input- Sensory association cortex of parietal, occipital and temporal lobes
2. Output- Sensory association cortex of parietal, occipital and temporal lobes
3. Function-Still being investigated
Internal capsule Anterior limb
1. Connects anterior nucleus with _____
2. Connects dorsomedial nucleus with _____
1. Cingulate gyrus
2. Prefrontal cortex
Internal capsule Posterior limb
1. Connects VA and VL with _____
2. Has _____ (posteriorly)and _____
(anteriorly) fibers
3. Has somatosensory fiber from _____ to the
postcentral gyrus
1. motor areas of cortex
2. corticospinal and corticobulbar
3. VPL/VPM
What is the Internal capsule Genu?
Transitional zone between anterior and posterior
limb
Retrolenticular
1. Connects the thalamus with the _____ and
_____
2. Contains what radiation?
1. Parietal and occipital lobes
2. Optic radiation
Sublenticular
1. Continuous with _____
2. Contains what 2 radiations
1. Retrolenticular
2. some optic radiation and auditory radiation
Arcuate nucleus
1. Produces:
• Supports the _____
2. Hormones enter capillaries in
3. _____ and then enter
4. _____ to reach
5. _____
6. Has neurons that produce dopamine
- Dopamine is a _____ inhibiting factor
1. Produces:
• Produces hypothalamic releasing hormones
- ACTH, GH, prolactin, TSH, GnRH-LH, FSH
• Produces inhibiting factors
2. tuberohypophyseal tract
3. tuberoinfundibular tract
4. Hypophyseal-portal vein system
5. Secondary capillary plexus of adenohypophysis
6. prolactin inhibiting factor
Hypothalamohypophyseal tract
1. Supraoptic synthesizes _____
2. Paraventricular synthesizes _____
3. Hormones are carried with carrier proteins
known as _____ and are released at axon terminals
4. Hormones released into bloodstream at
fenestrated capillaries of posterior lobe of
hypophysis (pituitary)
1. vasopressin (ADH)
- Vasoconstriction
- Antidiuretic function-increases absorption of water in
kidneys
2. oxytocin
- Contraction of uterine smooth muscle
- Contraction of myoepithelial cells in breast and assists in expression of milk from breasts
- Stimulates labour contractions
3. neurophysins
4. posterior lobe of hypophysis (pituitary)
Mamillary body
1. Part of the _____
2. Afferents from the _____
3. Efferents going to the _____ nuclei of the thalamus and brainstem
4. Damaged in _____
1. Limbic system
2. Hippocampus
3. Anterior nuclei
4. Wernicke encephalopathy
4 Hypothalamic afferent connections:
1. DLF = dorsal longitudinal fasciculus
2. MFB = medial forebrain bundle
3. ST = stria terminalis
4. VAP = ventral amygdalofugal pathway
3 Hypothalamic efferent connections:
1. DLF = dorsal longitudinal fasciculus
2. ST = stria terminalis
3. VAP = ventral amygdalofugal pathway
Preoptic nucleus
1. Regulates release of _____
2. Contains _____ nucleus
3. Lesion before puberty
4. Lesion after onset of puberty
1. Gonadotrophic hormones
2. Sexually dimorphic nucleus
- Sensitive to androgens and estrogens
3. Arrest sexual development
4. May result in amenorrhea or impotence
Hypothalamic Control of food and fluid intake
• Satiety center
1. _____ nucleus
2. Arcuate neurons receive information from _____ about stomach distension and glucose content in the stomach and intestines
3. Stimulation _____ eating
- Lesion leads to abnormal food intake
4. Bilateral lesions lead to _____
• Feeding and thirst centers
5. _____ hypothalamic area
- Stimulation leads to eating and increased water
intake
6. Lesions leads to _____ and _____
7. Bilateral lesions lead to _____
1. Ventromedial nucleus
2. Nucleus solitarius
3. Inhibits
4. Obesity
5. Lateral
6. aphagia and adipsia
7. anorexia
Hypothalamic Control of Sleep
1. _____ nucleus
- Neurons fire at ↑rate at night
2. producing hypothalamic neurons
- Extensive branching axons
• Go to thalamus and cerebral cortex
- Neurons are _____ when waking up
• Ascending reticular activating system
- Consciousness is attributed to continuous
signaling from reticular formation of the
brainstem to the thalamus and cortex
1. Suprachiasmatic
2. Histamine
3. Active
Thermoregulation
• Heat loss
- Many neurons in hypothalamus receive heat measurements
- 1. Most are in _____ nucleus
- Vasodilation and sweating
- 2. Lesion in _____ nuclei leads to increased body temperature (hyperthermia)
• Heat conservation
- Posterior regional hypothalamic nuclei
- Vasoconstriction, reduced sweating, piloerection
- 3. Lesion in _____ nuclei leads to poikilothermia (uncontrolled body temperature)
• 4. Axons from _____nuclei course through
posterior hypothalamus
1. Medial preoptic nucleus
2. Anterior regional hypothalamic nuclei
3. Posterior regional hypothalamic nuclei
4. Anterior regional hypothalamic nuclei
1. Brodmann's area 4
2. area 6
3. area 8
4. areas 44 & 45
5. Prefrontal cortex
6. areas 1, 2, 3
7. area 17
8. area 17, 18, 19
9. areas 41 & 42
10. area 22
1. Precentral Gyrus = Primary motor cortex
2. Premotor & supplementary motor areas
3. Frontal eye fields (eye movement)
4. Broca's area - language production
5. Goals & plans (executive decisions)
6. Primary somatosensory cortex
- Somatosensory association
- Visual association
- Supramodal association cortices
7. Primary visual cortex - receives input from thalamus &
Somatosensory association
8. higher level visual processing
9. Primary auditory cortex - receives input from thalamus
Wernicke's area
10. in hemisphere dominant for language (usually left)
comprehension and production of language
White Matter of Cerebral Hemisphere
1. Fiber?
- Interconnect various cortical regions within one
hemisphere
- Short association fibers connect adjacent gyri and
run transversely to long axis of sulci
- Long association fibers link distant areas of
cerebral cortex
2. Fibers?
- Connect corresponding regions of both
hemispheres
3. Fibers?
- Afferent and efferent fibers between cerebral
cortex and subcortical structures
1. Association fibers
2. Commissural fibers
3. Projection fibers
Central sulcus and surrounding gyri
1. Apraxia:

Language area (temporal)
2. Aphasia:
3. Alexia:
4. Agraphia:
5. Acalculi:
1. Apraxia: not being able to put together sensory with motor
2. Aphasia: can't recognize speech
3. Alexia: can't read
4. Agraphia: can't make picture
5. Acalculi: can't do math
Association fibers (slide 71)
• Superior longitudinal fasciculus
- 1. Largest bundle that connects anterior part of
frontal lobe to _____ and _____ lobes
- 2. Arcuate fasciculus connects gyri of frontal and temporal lobes for _____ function
• Inferior longitudinal fasciculus
- 3. From occipital to temporal lobes for _____ function
• Uncinate fasciculus
- 5. Anterior and inferior parts of frontal lobe with
temporal gyri related to _____ regulation
• Cingulum
- 6. Cingulate gyrus, connects frontal & parietal lobes with _____ & adjacent _____ gyri
1. Occipital and temporal lobes
2. Language function
3. Visual recognition function
4. Behavior regulation
5. Parahippocampal & adjacent temporal gyri
Arcuate fasciculus is the same thing as?
Superior longitudinal fasciculus
Commissural fibers
• Corpus callosum
- Connects corresponding regions of neocortex
except 1. _____
- Splenium interconnects occipital cortices for
2. _____
• Anterior commissure
- Interconnects inferior and middle temporal gyri
as well as 3. _____ regions
• Posterior commissure
- Fibers from pretectal nuclei involved in
_____ cross
• Part of parasympathetic fibers for CN ___
1. Temporal fields
2. Visual functions
3. Olfactory
4. Pupillary light reflex cross
5. CN III
Commissural fibers (cont.)
• Fornix or hippocampal commissure
- 1. _____ system of hippocampus that passes to
_____ of hypothalamus
- Connect hippocampal formations of both
hemispheres
- Links posterior columns of fornix
• Habenular commissure
- 3. Habenular nuclei receive afferents from
_____ nuclei and _____
- 4. Pass to habenular nuclei via _____
1. Efferent
2. mammillary bodies
3. amygdaloid nuclei and hippocampus
4. stria medullaris thalami
Projection fibers
• Internal capsule
- 1. Anterior limb connects mediodorsal nucleus of thalamus and _____ and _____
- Posterior limb
• Corticobulbar and corticospinal fibers
• 2. Connects ventral posterior nucleus of thalamus to _____
• 3. Connects ventral anterior and ventral lateral nuclei of thalamus to _____ regions of frontal lobe
• Corona radiata
• 4. Optic radiation-retrolenticular part of internal
capsule-_____ fibers
1. Prefrontal cortex and frontopontine fibers
2. primary somatosensory cortex
3. motor regions
4. Visual thalamocortical fibers
Cerebral Dominance
• 1. _____ - integration of sensory and visual input
to form size, form and texture
• 4 Dominant functions
• 3 Non-dominant functions
• Statistics
- More than 90% of adult population is righthanded and thus left hemisphere dominant
- 96% are left hemisphere dominant for _____
- Right handed verified by more left descending
fibers crossing over in pyramid
1. Stereognosis
2. Handedness, perception of language, writing, and speech
3. Spatial perception, recognition of faces and music
4. speech
Where images are put together; interpretation of what the image mean; visual association cortex
Calcarine sulcus
2 Output nuclei of basal ganglia:
1. globus pallidus interna
2. substantia Nigra Pars Reticulata
3 Intermediate nuclei of basal ganglia:
1. Globus pallidus externa
2. subthalamic nucleus
3. Substantia Nigra Pars Compacta
Functions of basal ganglia:
1. 3 Non-motor loops
Motor loop (focus of our journey)
4. Regulation of _____
- necessary for normal initiation
1. Executive/prefrontal loop
2. Limbic loop
3. Oculomotor loop
4. Upper motor neurons
Pathways of motor loop
1. direct pathway is overall?
2. Indirect pathway is overall?
1. overall excitatory
2. overall inhibitory
Effect of DA on pathways
1. Direct pathway:
2. Indirect pathway:
3. Overall:
1. Stimulates
2. inhibits
3. excitatory
Basal ganglia (caudate, putamen, and GP)
1. NT?
Cortex, thalamus, STN
2. NT?
Dopamine from substantia nigra pars compacta
3. Acts on?
1. GABAergic = inhibitory
2. Glutamatergic = excitatory
3. Putamen
1. 2 hyperkinetic movement disorders:
2. 2 hypokinetic movement disorders:
1. Hemiballismus & Huntington's disease
2. Parkinson's disease and drug induced (neuroleptics, MPTP)
Parkinson's disease
1. loss of __ neurons in substantia nigra
2. 4 cardinal symptoms:
1. DA
2. Bradykinesia, akinesia, rigidity, tremor
2 Input nuclei of basal ganglia:
Corpus striatum
-Caudate
-Putamen
Which part of Substantia nigra has DA?
Substantia nigra pars compacta
MTPT causes?
Parkinson-like effects
Direct pathway (excitatory):
Cortex (Glutamate +) -> Putamen (GABA -) -> GP interna (GABA -) -> VA/VL thalamus (Glutamate +) -> Cortex
Indirect pathway (inhibitory):
Cortex (Glutamate +) -> Putamen (GABA -) -> GP externa (GABA -) -> Subthalamic nucleus (Glutamate +) -> GP interna (GABA -) -> VA/VL thalamus (Glutamate +) -> Cortex
1. DA from substantia nigra pars compacta stimulates what?
2. Inhibits what?
1. Putamen in Direct pathway
2. Putamen in Indirect pathway
Berry aneurysms occur where?
Anterior circle of Willis
Arteriovenous malformations
Arteriovenous malformations - arterioles nest with venules bypassing the brain
Amaurosis fugax
1. Symptoms?
2. Caused by?
1. Transient monocular blindness
2. Plaque formation that breaks off and occludes the internal carotid artery or the common carotid artery
Which side of the body lacks the brachiocephalic trunk?
Left
Blood supply to brain:
1. Flow rates < __ ml/100 gm/min induce ischemia
2. at flow rates of < __ ml/100 gm/min, infarction occurs.
1. < 25
2. < 12
1. Cause of hemorrhagic stroke
2. 3 Causes of Thrombotic/Embolic stroke
1. Hypertensive disease
2. Hematologic disorders - sickle cell
Atherosclerosis
Myocardial infarction
(N138) Arterial Supply to the Brain:
1. Anterior Circulation
Provided by branches derived from the _____.
2. Posterior Circulation
Provided by branches derived from the _____.
1. Internal carotid a.
2. Vertebral-basilar aa.
The Anterior Circulation:
Perfusion is provided by branches of the internal carotid artery (ICA).
Regions of the ICA
Cervical portion - no branches
Petrous portion - (in carotid canal of the temporal bone) - 2 branches:
Cavernous portion - some supply to the CNs in the cavernous sinus - 4 CNs:
1. Caroticotympanic a. & A. of Pterygoid canal
2. V ganglion, III, IV, & VI
(N85) The _____ branch of the Ophthalmic a. anastomoses with the angular branch of the facial artery.
Supratrochlear branch
Syndrome?
Orthograde perfusion via ICA => Circle of Willis. Retrograde perfusion via Posterior cerebral artery => Basilar artery => Vertebral artery => Subclavian artery.

This can occur due to occlusion of the aorta between the origins of the left common carotid artery and left subclavian artery by atherous plaque formation.
Subclavian Steal Syndrome
The vertebral-basilar a. junction occurs where?
Pontomedullary junction
Occlusion of what aa. supplying the eye leads to blindness?
Posterior ciliary aa. (encircles the optic n. as it exits the eye)
Rupture is the leading cause of intracerebral (intraparenchymal) hemorrhage
Medial striate aa.(lenticulostriate aa) - extremely important vessels
Reason: Rupture is the leading cause of intracerebral (intraparenchymal) hemorrhage
(N139-140) Anterior cerebral artery A1 branch
Medial striate aa.(lenticulostriate aa)
(N139-140) Anterior cerebral artery A2 branches 4:
1. Recurrent artery of Hubner
2. Frontopolar branch
3. Callosomarginal branch
4. Pericallosal branch
"Artery of Cerebrovascular Disease!"
Middle cerebral a.
(N139) Middle cerebral artery M1 branch:
Lateral striate (lenticulostriate) arteries - Extremely important vessels
(N140) Middle cerebral artery M2 branches 5:
1. Temporopolar artery
2. Precentral (Rolandic) branches
3. Postcentral (Rolandic) branches
4. Angular branch
5. Posterior temporal branch
The anterior cerebral artery supplies the medial surfaces of the cerebral hemisphere (motor cortex for the ___) up to the parieto-occipital fissure.
Leg
Stroke of the middle cerebral artery can cause blindness b/c of proximation to ____ radiations
Optic
Anterior Choroidal Artery (N-137) supplies 3:
1. Optic tract
2. Choroid plexus in inferior horn of lateral ventricle
3. Thalamic nuclei posteriorly
3 Branches from Vertebral aa.
1. Posterior Spinal aa.
2. Posterior Inferior Cerebellar aa. (PICA)
3. Anterior spinal a.
What artery pierces and travels on top of the Tentori cerebellum?
Posterior cerebral a.
What artery supplies macular vision on posterior occipital lobe and can preserve central vision when all else is lost?
Posterior temporal a. - branches from Middle cerebral a.
What artery supplies the primary visual cortex of the brain?
Posterior cerebral a.
Posterior inferior cerebellar a. supplies:
1. Posterior lateral medulla (Wallenberg's syndrome)
2. 4th ventricle
3. choroid plexus
4. posterior inferior cerebellum.
(N141) Basilar A. Branches 6:
1. Anterior inferior cerebellar artery (a.i.c.a.)
2. Labyrinthine (internal auditory) artery
3. Paramedian(pontine) arteries
4. Long and short circumferential arteries
5. Superior cerebellar artery
6. Posterior cerebral artery
Blood supply to the brainstem
Basilar a.
Blood supply to superior cerebellum and nuclei
Superior cerebellar a.
The posterior cerebral artery's, P1,P2 and P3 segments supply respectively, the:
1. hypothalamus
2. post. lat. thalamus (thalamogeniculate br.)
3. choroid plexus (post. choroidal br.)
4. midbrain peduncles
5. tectum (quadigeminal brs.)
6. basal surface of the temporal lobe (ant. and post. temporal brs.)
7. all of the occipital lobe of the brain, and especially the visual cortex. (calcarine br.)
1. Deep (internal) cerebral veins
Tributaries 3:
2. Great Vein of Galen
Tributary:
1. Thalamostriate vein
Caudate vein
Septal vein
2. Deep (internal) cerebral veins
Straight sinus (dural sinus)
Tributaries 4:
1. Great vein of Galen
2. Basal vein of Rosenthal
3. Inferior sagittal sinus
4. Superior cerebellar veins
Confluence of the sinuses
Tributaries 3:
1. Superior sagittal sinus
2. Straight sinus
3. Occipital sinus
Superior Petrosal sinus drains into?
Sigmoid sinus -> Inferior Petrosal sinus -> Internal Jugular v.
Cavernous sinus is drained by?
Inferior Petrosal Sinus
Cavernous Sinus
Tributaries 5:
1. Sphenoparietal sinus
2. Intercavernous sinus
3. Circular sinus
4. Superior and Inferior ophthalmic veins
5. Pterygoid plexus of veins
Superficial Cortical Veins 4:
1. Middle cerebral vein
2. Bridging veins - associated with subdural hematoma
3. Large (Superior) anastomotic Vein of Trolard drains to the superior sagittal sinus. It is usually observed in the postcentral sulcus of the brain.
4. Small (Inferior) Anastomotic vein of Labbe' drains to the transverse (lateral ) dural sinus from the lateral fissure.
1. The cardinal feature of brainstem stroke involves an _____
2. Cerebellar signs, if present, are _____
3. A dissociated sensory deficit over the face and half the body can indicate that a lesion is within the _____
1. ipsilateral peripheral cranial nerve involvement in combination with
2. contralateral weakness or sensory deficit.
3. ipsilateral and observed on the same side as the brainstem infarct.
4. brainstem between the pons and spinal level, C3.
1. A hemi-sensory loss involving all modalities indicates a lesion lies in the _____
2. Bi-laterality of both motor and sensory signs is almost certain evidence of a _____.
3. When hemiplegia or hemiparesis and sensory loss are coextensive, the lesion usually lies ____.
4. Vertigo is a common early symptom of _____; however vertigo is only caused by central nervous system problems about 5% of the time; inner ear problems are the most common source of vertigo.
1. upper brainstem or beyond.
2. brainstem lesion.
3. supratentorially.
4. brainstem strokes
Gracile nucleus contains the ___ order neurons of the dorsal column system fibers of the gracile fasciculus synapse here
2nd
Spinal nucleus of CN V contains ___ order neurons for _____ from head axons become part of trigeminothalamic tract
1. 2nd
2. Pain and temperature
1. Internal arcuate fibers contain:
2. Medial lemniscus contains:
1. axons of gracile & cuneate nuclei
2. crossed axons of contralateral gracile and cuneate nuclei
Vestibular nuclei is composed of 4 nuclei: medial, inferior, lateral & superior
receives afferent fibers from inner ear labyrinth
sends efferent fibers to
cerebellum, CNs III, IV, & VI, and spinal cord
1. Solitary nucleus and tract receives afferent fibers from CN _ (taste pathway)
2. and from _____ (BP regulation) via the solitary tract
1. CN IX, X, XI
2. Baroreceptors in carotid and aortic sinuses
Reticular formation sends efferent fibers to various regions of the CNS responsible for the _____
State of awakeness
1. SNS Arises from spinal cord segments __ through __
2. Sympathetic neurons produce the _____ horns of the spinal cord
3. Preganglionic fibers pass through the _____ and synapse in the ganglia
4. Fibers from _____ form splanchnic nerves and synapse with collateral ganglia
1. T1 thru L2
2. Lateral
3. White rami communicantes
4. T5-L2
SNS Outflow
1. Paravertebral (sympathetic chain)
2. Prevertebral (collateral) ganglia
1. Superior, middle, inferior cervical
2. Celiac, superior and inferior mesenteric
1. Head, neck, heart
2. Bronchi, lungs
3. Upper limb
4. Esophagus
5. Stomach, spleen, pancreas
6. Liver
7. Small intestine
8. Kidney, reproductive organs
9. Lower limb
10. Large intestine, ureter, urinary bladder
1. T1 - T5
2. T2 - T4
3. T2 - T5
4. T5 - T6
5. T6 - T10
6. T7 - T9
7. T9 - T10
8. T10 - L1
9. T10 - L2
10. T11 - L2
Viscerosensory Afferents
Parasympathetic Cranial Nerves
CN III, VII, IX, and X
CN III has no sensory tracts
1. CN VII has no _____ tracts
2. CN IX
3. CN X
1. viscerosensory tracts
2. Carotid body and sinus chemo- and baro- receptors
Nociceptive afferents from the oropharynx
3. Aortic body and arch chemo- and baro- receptors
Physiologic sensations
Cholinergic receptors:
The two types of receptors that bind Ach: nicotinic and muscarinic
These are named after drugs that bind to them and mimic ACh effects
Type of receptor?
1. Nicotinic =
2. Muscarinic =
1. Ligand-gated ion channel
2. G-protein linked
Fight or flight response is coordinated by the?
hypothalamus
B2 receptor NT?
Epi>>NE
1. The _____ is the main integration center of ANS activity
2. Subconscious cerebral input via _____ lobe connections influences hypothalamic function
Other controls come from the cerebral cortex, the reticular formation, and the spinal cord
1. Hypothalamus
2. Limbic
Levels of ANS control:
1. Spinal cord 3:
2. Brainstem 3:
3. Hypothalamus
Integration of homeostasis & behavior 5:
4. Limbic system 4:
1. Spinal cord - micturition, defecation, erection & ejaculation
2. Brainstem - blood pressure, respiration, heart rate
3. temperature regulation
blood volume, blood pressure
heart rate
eating & drinking
reproduction
4. feeding, fighting, fleeing, reproduction
Syndrome?
Disruption of sympathetic innervation
of head and neck
Symptoms:
pupillary constriction
levator muscles
partial ptosis (upper lid)
inverse ptosis (lower lid)
withdrawal of eye into orbit
vasodilation of facial skin
loss of facial sweating
Miosis- predominance of PNS tone (CIII)
No PNS innervation to skin and levator
muscles
Lack of SNS input produces ptosis,
vasodilation, and lack of sweating
Horner's Syndrome
3 Causes of Horner's Syndrome:
1) Destruction of preganglionic neurons
in the spinal cord
2) Interruption of the cervical sympa-
thetic chain ganglia
3) Damage in the brainstem to nuclei
that activate the SNS preganglionic
neurons
Disease?
Lack of PNS ganglionic cells in a segment of
the myenteric plexus
no peristalsis in segment which results
in its narrowing and spasticity
accumulation of fecal matter proximal
to affected segment- megacolon
typical- rectosigmoid region
less common- long segment- entire
colon can be affected
Hirschsprung's Disease (megacolon)
Neuromuscular blockers:
1. Non-Depolarizing Blockers
2. Depolarizing Blocker
1. Tubocurarine (Curare), Rocuronium
2. Succinylcholine
Anticholinesterase Agents 4:
Neostigmine, edrophonium
Tacrine, Donepezil
- Treatment of Alzheimer's Disease
Muscarinic agonist
Bethanechol
Muscarinic Antagonists:
1. 2 Tertiary amines - can enter CNS
2. Synthetic quaternary amine - can NOT enter CNS
**Quaternary compounds can block nicotinic receptors and may have ganglion or neuromuscular blocking action
1. Atropine, Scopolamine
2. Ipratropium
PNS Primary Effect:
Inhibition of the SA node in the heart
= decreased _____
PNS does not innervate the vasculature-
exogenously administered Ach causes
_____
1. Chronotropy
2. Vasodilation
PNS effects on Eye muscle:
1. _____ via contraction of iris sphincter (circular muscle)
2. _____ via ciliary muscle contraction
1. Miosis
2. Accommodation
Therapeutic uses of muscarinic receptor agonists:
Agonist?
Ophthalmic surgery to produce rapid miosis
ACh
Therapeutic uses of muscarinic receptor agonists:
Agonist?
Most frequently used clinically
Postoperative or neurogenic urinary retention
Postoperative atonic bowel without obstruction
Gastroesophageal reflux (GERD) (rarely used); proton pump inhibitors preferred; H2 receptor antagonists used.
Bethanechol
Used to treat Parkinson's disease (general drug type)?
Antimuscarinics - Used as adjuncts along with drugs capable of elevating dopamine levels or activating dopamine receptors
Antimuscarinic effects on eye:
1. _____ = (dilation of iris sphincter)
2. _____ = (relaxation of ciliary muscle)
1. Mydriasis
2. Cycloplegia
Contraindications for muscarinic receptor agonists:
Bronchial asthma
Urinary obstruction
Peptic ulcer
Gastrointestinal lesion or obstruction
Hyperthyroidism
(may induce atrial fibrillation)
Coronary insufficiency
Toxicity of muscarinic receptor agonists:
Bradycardia
Syncope (caused by asystole)
Orthostatic hypotension
Cardiac dysrhythmias
Gut or urinary urgency
Diaphoretic effects (sweating)
Sialogogic effects (salivation)
Abdominal cramping
Clinical importance of anticholinesterases
1. Reversal of neuromuscular blockade by nondepolarizing agents
2. Diagnosis and treatment of myasthenia gravis
Reactivates cholinesterase enzyme?
Pralidoxime (2-PAM)
Muscarinic Antagonists effects on CNS
Action at respiratory center
therapeutic dose: faster deeper breathing
larger doses: depression of respiration
Cerebral centers:
low doses: sedation
high doses: restlessness, amnesia, delirium
higher doses: stupor; coma
Note: with therapeutic doses, atropine generally has less CNS sedative effects than scopolamine
Order of appearance of physiological effects with increasing dosage of Muscarinic antagonists:
1. Decreased - Salivary, bronchial, sweat secretions
2. Decreased - Micturition
3. Tachycardia, mydriasis, cycloplegia
4. Decreased - Intestinal motility
5. Decreased - Gastric secretion
Emergency Medicine
Drug?
Drug of choice for symptomatic sinus bradycardia
May be beneficial in presence of AV nodal block or ventricular asystole
2nd drug, after epi or vasopressin, for asystole or bradycardic pulseless electrical activity
Organophosphate poisoning
- Extremely large doses may be needed
Atropine
Respiratory disorders:
Drug?
Inhalational drug to reverse bronchial constriction and secretion
Emphysema, chronic bronchitis (COPD).
Sometimes asthma
Ipratropium
Motion sickness
_____ is useful in prophylactic treatment via CNS action in vestibular nuclei and reticular formation
Scopolamine
Therapeutic uses of antimuscarinics:
Anesthesiology:
Anesthesiology
Prevent bronchospasm
Prevention of bronchial and salivary secretions
Reversal of reflex bradycardia or hypotension during surgery
Contraindications for Antimuscarinics
Glaucoma
Prostatic hypertrophy
Toxicity more severe in children
Toxicity of Atropine-like drugs (Antimuscarinics)
Xerostomia
constipation
Urinary retention
hyperthermia
Mydriasis
headache
Blurred vision
Dizziness
Flushing, dry skin
Excitement
Heart palpitation
Mental confusion, memory loss, hallucinations
1. alpha1 family:
2. alpha2 family:
1. alpha1 family: a1A, a1B, a1D
2. alpha2 family: a2A, a2B, a2C
1. Epinephrine has greater potency for what type of receptor?
2. Efficacy is greater at what type of receptor?
1. Beta
2. Alpha
Inotropic:
Inotropic: Affecting the FORCE of muscle contraction. An inotropic heart drug is one that affects the force with which the heart muscle contracts.
Chronotropic:
Affecting time/rate
Cardiac Output =
Cardiac Output = Heart Rate x Stroke Volume
Epinephrine - Blood Vessels
1. Skeletal muscle arterioles: Types of receptors present?
2. - Physiological quantities cause? (type of receptor responsible)
3. - Pharmacological doses cause? (type of receptor responsible)
4. Veins: Type of receptor present? predominate action?
5. Coronaries: predominate action?
6. Kidney, skin, mucosa: action?
7. Cerebral: action?
1. both Alpha1 and Beta2 receptors are present
2. Vasodilation (Beta2)
3. Vasoconstriction (Alpha1)
4. Alpha1>>>>Beta2; constriction
5. Vasodilate (>Beta2)
6. Vasoconstriction
7. Unchanged
Baroreceptor control of BP:
1. Blood pressure increases suddenly
2. Blood pressure decreases suddenly
1. Blood pressure increases suddenly
Sympathetic tone decreased
Vagal tone to the SA node increased
2. Blood pressure decreases suddenly
Sympathetic tone increased
Vagal tone to the SA node decreased
1. Pulse pressure (PP) =
2. Peripheral resistance =
- Directly reflected by?
3. Mean arterial pressure (MAP) =
1. Pulse Pressure (PP) = difference between systolic and diastolic pressure
2. Peripheral Resistance = determined by the arterioles - directly reflected in the diastolic blood pressure (DP)
3. Mean Arterial Pressure (MAP) = DP + (0.33 x PP)
Isoproterenol acts at what type of receptors?
Beta1/2 ONLY!
Epinephrine metabolic effects 2:
Calorigenic effect and tremors in skeletal muscle (Beta2).
Mechanisms related to increased glycogenolysis (Beta2) and lipolysis (Beta3) at various organ sites (liver, skeletal muscle and adipocytes.)
4 Clinical uses for Epinephrine:
1. Asthma. Administered by inhalation. Bronchodilation (Beta2) and inhibition of antigen-induced histamine release.
2. Anaphylactic shock (give IV or SC) Improves breathing by same mechanisms as in 1 above, plus increases blood pressure and reverses edema (Alpha1).
3. Infiltration with local anesthetics. (constricts blood flow to localize anesthetic)
4. Topical for hemostasis (bleeding).
4 Epinephrine adverse effects:
1. Arrhythmias
2. Cerebral hemorrhage
3. Necrosis distal to site of injection (potential problem with infiltration anesthetics)
4. CNS effects: anxiety, headache
2 Epinephrine contraindications:
1. Hypertension
2. Angina pectoris
Which are longer acting? Epi and NE or Synthetic catecholamines?
Non-catecholamines are metabolized more slowly (they are not acted upon as readily by monoamine oxidase [MAO], and often they are not stored in vesicles). Therefore they are generally longer acting; some are effective p.o.
Non-selective alpha-blockers?
Phentolamine
Phenoxybenzamine
Non-selective beta-blocker?
Propranolol
Alpha1 selective blocker?
Prazosin
Beta1 Selective blockers?
Metoprolol
Atenolol
2 Clinical uses for phentolamine
1. Pheochromocytoma (catecholamine secreting tumor of adrenal medulla) -- control acute hypertensive crisis
2. Treat necrosis due to vasoconstrictors such as NE and phenylephrine (should be a rare use)
Side effects of phentolamine
Orthostatic hypotension**
Hypotension
- Distinguish the concept of orthostatic hypotension from hypotension
Tachycardia**
Hypotension caused by phentolamine elicits increased sympathetic nervous system activity, leading to tachycardia.
A non-selective a1/a2 blocker blocks the presynaptic autoreceptor function of NE
This is not important in the vasculature, where the drug blocks a1 receptors and NE does not stimulate b2 receptors.
However, at the heart, the b1 effects of NE are unantagonized, and the reflex tachycardia is profound
Nausea
Diarrhea
- Combined alpha blocking and muscarinic/histaminic agonist actions
Phenoxybenzamine
1. Mechanism: Binds _____ to alpha-1 and alpha-2 adrenergic receptors. i.e. non-selective alpha blocker
Described as a non-competitive (irreversible) blocker.
Onset is slow (several minutes for formation of covalent linkages)
2. Offset is very slow elimination t1/2 of __ hours. New receptors must be synthesized.
1. Covalently
2. 24 hours
2 Effects of Phenoxybenzamine
1. Vascular. Blocks the effects of endogenous NE -- reduces blood pressure.
2. Cardiac. Reflex tachycardia.
Reducing BP causes sympathetic activation. Because alpha-2 receptors on adrenergic nerves are blocked, this further increases NE release at the heart, where NE can act on beta-1 receptors.
2 Uses for Prazosin
1. Benign prostatic hypertrophy
b.i.d. dosing and orthostatic hypotension limit use of this agent compared to newer drugs
2. Hypertension
Orthostatic hypotension limits usefulness
Reflex tachycardia is minimal if at all
Effects of propranolol
Heart (decreases CO)
Decreases HR (negative chronotrope)
Decreases contractility (negative inotrope)
Decreases spontaneous pacemaker activity (depresses ectopic foci more than SA node)
Blood vessels
Reduction in renin release (renin release is controlled by b1 receptors in the kidney), leading to decreased angiotensin and decreased aldosterone
Results in a slow developing decrease in peripheral resistance
Clinical uses for propranolol
****1. Angina pectoris.
Reduces cardiac work and O2 consumption.
****2. Hypertension.
Decrease in cardiac output and decrease in peripheral resistance (due to blockade of renin release).
Won't be tested:
3. Migraine headache (Prophylactic treatment)
4. Arrhythmias.
5. Pheochromocytoma
6. Thyrotoxicosis
7. Adjunctive treatment of anxiety (particularly performance anxiety related to fine motor skills)
8. Reduce mortality post MI
9. Management of heart failure
Side effects of Propranolol
Common:
dizziness, tiredness, nausea, depression, vivid dreams, impotence (Note: these are all related to CNS effects that are poorly understood scientifically)
constipation, diarrhea
Severe reactions: rash, purpura, fever.
Chronic use: significantly increased likelihood of developing Type 2 diabetes; increased VLDL and decreased HDL cholesterol
In diabetics, delays recovery from hypoglycemia.
Contraindications of propranolol
Asthma
Obstructive pulmonary disease
Cardiogenic shock
Acute treatment of heart failure (contrast this to use of beta blockers in management of stable heart failure)
3rd degree heart block
2nd degree heart block
Propranolol drug interactions
Additive with hypotensive agents
Prolongs hypoglycemia in patients taking hypoglycemic agents. Masks signs of _____.
Mask symptoms of hyperthyroidism
Hypoglycemia
Describe the functions of each Descending Brainstem Medial tract:
1. Vestibulospinal
2. Reticulospinal
3. Tectospinal
1. Vestibulospinal
Paraveterbral extensors and proximal limb extensors (posture and balance)
2. Reticulospinal
Through gamma MNs, maintaining posture and modulating muscle tone
3. Tectospinal
Head movements for orienting reactions
Descending Brainstem Lateral Tract
1. Describe function of Rubrospinal Tract:
2. control distal limb muscles
3. innervating proximal limb _____ (upper limb)
Humans w/ corticospinal lesion, it provides remaining function
1. Goal-directed movements through interneurons on MNs
2. Distal
3. Flexors
Decorticate Rigidity
1. Patient has _____ of upper limbs and _____ of lower limbs.
2. Section through neural axis _____.
3. The resulting unchecked rubrospinal drive overexcites _____ motor neurons which in humans is limited to upper limbs.
1. Flexion; extension
2. Rostral to Superior colliculus
3. Flexor
Decerebrate Rigidity
Patients with trauma, vascular disease or tumors may present this way.
1. Section through the neural axis ______ produces decerebrate rigidity.
The tonic over activity due to the influence of sensory stimuli from _____ (gamma rigidity) and _____.
*All extensors are contracted
*Rubrospinal tract is not part of equation
1. Between the colliculi
2. Reticulospinal tract
3. Vestibulospinal tract
Torsional movements do not change the line of sight, but rotate the eye around it:
1. _____ rotates the top of the cornea toward the nose.
2. _____ rotates it away from the nose.
1. Intorsion
2. Extorsion
1. Superior rectus (CN III)
2. Inferior rectus (CN III)
3. Inferior oblique (CN III)
4. Superior oblique (CN IV)
1. elevation and intorsion
2. depression and extorsion
3. extorsion and elevation
4. intorsion and depression
1. Function of CN III (Oculomotor)
2. Location
1. Controls sphincter pupillae muscle of the iris and the ciliary muscle.
2. Location: midbrain at the level of the superior colliculus.
1. Lesions to the abducens nucleus paralyze the _____ medial rectus. Patient cannot direct the gaze to the side of the lesion.
2. A nuclear lesion may also involve the nearby nucleus or axons of the _____ nerve, causing paralysis of all the _____ facial muscles.
1. Contralateral
2. Facial n.
3. Ipsilateral
3 Neuronal systems that keep the fovea on a visual target in the environment:
1. Saccade (rapid, ballistic movements shift fovea rapidly to visual target)
2. Smooth pursuit (keep image of moving target on fovea)
3. Vergence movements move eyes in opposite directions so that image is positioned on both foveas (converge for near and diverge for far)
Rapid, ballistic eye movements shift fovea rapidly to visual target (term?)
Saccade
Keep image of moving target on fovea (term?)
Smooth pursuit
Move eyes in opposite directions so that image is positioned on both foveas (term?)
(_____ for near and _____ for far)
1. Vergence movements
2. Converge
3. Diverge
2 Neuronal systems that stabilize the eye during head movement:
1. Vestibulo-ocular reflex (VOR) movements hold images still on fovea during head movements
2. Optokinetic movements hold images during sustained head movement & supplements VOR
Hold images still on fovea during head movements (neuronal system?)
Vestibulo-ocular reflex (VOR) movements
Hold images during sustained head movement & supplements Vestibulo-Ocular Reflex (VOR) (neuronal system?)
Optokinetic movements
1. The _____ system holds the eye still during intent gaze.
2. Neural center (fixation zone): most rostral portion of the _____.
Fixation requires active suppression of eye movements.
3. Neurons in the fixation zone inhibit _____.
1. Fixation system
2. Superior colliculus
3. Saccades
Patients use head tilt to eliminate diplopia caused by a lesion to which CN?
CN IV
********(Convergence) To look from a distant object to a closer one, three actions are yoked:
1. Eyes _____ by simultaneous contraction of both MR muscles (a disconjugate movement).
2. Pupil is _____ increasing depth of field of eye.
3. Curvature of lens is increased which increases refractive power of lens to focus near object on fovea (_____).
1. Converge
2. Constricted
3. Increased; accommodation
Visual neurons of cortex with binocular receptive fields use _____ to drive the vergence system.
Retinal disparity
1. Premotor neurons related to vergence are in the _____ of the _____ area close to the Oculomotor Nucleus.
2. Cells of SOA project to _____ and _____ motor neurons.
3. Cells of SOA also project to motor neurons of the _____ nucleus that controls the pupil and lens.
4. Vergence and Saccadic systems operate _____:
A lesion in the Center for Lateral Gaze will impair horizontal saccades but vergence movements in horizontal plane are not affected.
1. Midbrain; supraoculomotor area (SOA)
2. Medial and lateral rectus motor neurons
3. Edinger-Westphal nucleus
4. Independently
1. Center for Vertical Saccades -
2. Center for Horizontal Saccades -
3. Both centers provide coordination between oculomotor and abducens nuclei for _____ and _____ movements.
4. Cortical control of H & V saccades work through _____.
1. Rostral interstitial nucleus of the Medial Longitudinal Fasciculus (riMLF)
2. Paramedian pontine reticular formation (PPRF)
3. Saccadic and smooth pursuit movements
4. Superior colliculus
1. In the saccadic system, cortical control is _____.
2. Rapid movements are?
1. Contralateral
2. Preprogrammed
Medial & Lateral Vestibular Nuclei initiate?
Vestibular-ocular Reflex (VOR)
MLF syndrome is also referred to as?
internuclear ophthalmoplegia
Neurons involved in Saccade:
1. _____ relay signals from the cortex and provide velocity component. Also provide inhibition to _____medial rectus and _____ lateral rectus.
2. Abducens motor neurons project excitation to _____ lateral rectus while
3. The _____ project to contralateral CN III - medial rectus through MLF.
4. _____ inhibit burst neurons to prevent unwanted movements but are inhibited during saccade.
Abducens and oculomotor motor neuron signals contains both velocity and position signals to eye muscles.
5. Position signal provided by neurons in _____ and _____.
1. Burst neurons; ipsilateral; contralateral
2. Ipsilateral
3. Interneurons
4. Omnipause neruons
5. Nucleus prepositus hypoglossi and medial vestibular nucleus
Signals needed for horizontal gaze:
1. Signal to initiate a voluntary saccade (to left) originates in _____ (area?).
2. Signals related to target of saccade comes from _____ (visual info).
3. Signal from oculomotor & abducens motor neurons to eye muscles contains both _____ and _____ (keeps eye on target) components.
1. Contralateral cortical frontal eye field (area 8)
2. Parietal cortex
3. Velocity and position
Cortical control of saccades:
1. Centers for Horizontal (PPRF) and Vertical (riMLF) gaze receive commands from _____
2. Superior colliculus receives excitatory commands from ____ and
3. inhibitory commands from _____
4. Substantia nigra is inhibited by _____ which is excitated by _____.
5. Saccade centers also receive commands directly from _____
1. Superior colliculus
2. Frontal eye field and parietal cortex
3. Substantia nigra
4. Caudate nucleus; Frontal eye field
5. Contralateral frontal eye field
Unlike saccadic movements, central (cortical) control of smooth pursuit is _____
Ipsilateral
Cortical control of smooth pursuit:
Frontal eye fields is important for initiating pursuits movements.
1. A visual area in _____ provides sensory information needed to guide pursuit movements.
2. Motion sensitive neurons in temporal cortex calculate velocity of the target which is sent to _____ (flocculus & vermis) via the _____.
3. The temporal cortical neurons provide _____ signal designed to keep image of target on fovea.
4. Cerebellar velocity signals correlated with pursuit are sent to _____ and _____ which also drives horizontal gaze.
1. Temporal cortex
2. Cerebellum; Pontine nuclei
3. Continuous
4. Paramedian pontine Reticular fibers (PPRF) and medial vestibular nucleus
Vestibulo-Ocular Reflex (VOR) to Left:
1. Leftward head rotation excites the left horizontal canal which excites neurons that evoke _____ eye movement.
2. ___ vestibular neurons send excitatory signals to left oculomotor - medial rectus motor neurons.
3. Medial vestibular neurons send excitatory signals to ____ abducens - lateral rectus motor neurons.
4. ___ vestibular neurons send excitatory signals to abducens interneurons (which project to ____ oculomotor medial rectus neurons via MLF).
5. _____ vestibular neurons send inhibitory signals to abducens left lateral rectus neurons and abducens interneurons which inhibit _____ oculomotor medial rectus neurons via MLF.
1. Rightward
2. Lateral
3. Right
4. Medial; left
5. Medial; right
Lesion of right FEF: Inability to look to the ____ and eyes (at rest) deviate to the _____ because the left frontal eye field is unopposed.
1. Left
2. Right
Lesion of the left center for lateral gaze: Inability to make conjugate shift to the ____
Left
Lesion of right MLF (Internuclear Ophthalmoplegia): inability of _____ eye to adduct when looking to the left
Right
Horner's syndrome
Loss of sympathetic innervation:
miosis: reduction in pupil diameter due to unopposed action of parasympathetic innervation
ptosis: drooping of eyelid due to loss of innervation to superior tarsal muscle
enophthalmos: apparent sinking of eyeball in socket because of the interrupted innervation
anhidrosis: lack of sweating on affected side
3 Causes of Horner's syndrome:
1. Occlusion of the posterior inferior cerebellar artery (Wallenberg)
2. Tumor in the lung apex or occlusion of anterior spinal artery
3. Lesion associated with the carotid artery
Mesencephalon (Midbrain)
1. Superior posterior (dorsal) boundary
2. Inferior posterior (dorsal) boundary
3. Superior anterior (ventral) boundary
4. Inferior anterior (ventral) boundary
1. Posterior commissure of diencephalon
2. Line drawn immediately caudal to the site of emergence of CN IV (trochlear n.)
3. Caudal to mamillary bodies of hypothalamus
4. Superior pontine sulcus at the pontomesencephalic junction
Metencephalon (Pons)
1. Superior posterior (dorsal) boundary
2. Inferior posterior (dorsal) boundary
3. Superior anterior (ventral) boundary
4. Inferior anterior (ventral) boundary
1. Caudal to site of emergence of the trochlear n. (CN IV)
2. Stria medullaris on the floor of the fourth ventricle
3. Superior pontine sulcus at the pontomesencephalic junction
4. Inferior pontine sulcus at the pontomedullary junction
Myelencephalon (Medulla oblongata)
1. Superior posterior (dorsal) boundary
2. Inferior posterior (dorsal) boundary
3. Superior anterior (ventral) boundary
4. Inferior anterior (ventral) boundary
1. Stria medullaris of the fourth ventricle
2. Plane just rostral to C1 ventral root emergence and caudal to the decussation of the pyramids
3. Inferior pontine sulcus at the pontomedullary junction
4. Line drawn just caudal to the decussation of the pyramids
1. Superior colliculi of the tectum contains _____ reflex centers
2. Inferior colliculi of the tectum contains _____ reflex centers
1. Optic reflex centers
2. Auditory reflex centers
Corpora quadrigemina of the Tectum
Superior and inferior colliculi of tectum
If a cranial nerve innervates a structure derived originally from _____ it has the term "somatic" as part of its functional composition.

If the cranial nerve innervates a structure derived originally from _____ it has the term "visceral" as part of its functional composition.

Branchial arch skeletal muscle innervated by cranial nerves is also designated, "visceral".
1. Mesoderm
2. Endoderm
Remember that cranial nerves are peripheral nerves; they are protected and myelinated if necessary by _____ cells
(Ex. Acoustic neuroma or Schwannoma)
Cranial nerves that innervate muscle are _____ neurons.
1. Schwann cells
2. Lower motor neurons
Wallenberg's Syndrome
Posterior Inferior Cerebellar Artery (PICA) thrombosis "Medullary Syndrome", Ipsilateral: ataxia, facial pain & temp; Contralateral: body pain & temp
Parinaud's Syndrome
Disorder resulting from a lesion of the dorsal midbrain; characterized by impaired upward vertical gaze and loss of the pupillary light reflex. See gaze palsy, Sylvian aqueduct syndrome, and midbrain syndrome.
Benedickt's Syndrome
It is characterized by the presence of an CN III oculomotor nerve palsy and cerebellar ataxia including tremor. Neuroanatomical structures affected include CNIII nucleus, Red nucleus, corticospinal tracts, brachium conjunctivum, and cerebellum. It is very similar in etiology, morphology and clinical presentation to Weber's syndrome; the main difference between the two being that Weber's is more associated with hemiplegia (i.e. paralysis), and Benedikt's with hemiparesis (i.e. weakness).
Claude-Weber Syndrome
This lesion is usually unilateral and affects several structures in the midbrain including:
substantia nigra
corticospinal fibers
corticobulbar tract
oculomotor nerve fibers
It is caused by midbrain infarction as a result of occlusion of the paramedian branches of the posterior cerebral artery or of basilar bifurcation perforating arteries.
Millard-Gubler Syndrome
Ipsilateral loss of VII and contralateral loss of CST
Foville's Syndrome
Foville's syndrome, which is caused by a dorsally located infarction in the caudal part of the pons, comprises ipsilateral CN VI palsy and lower motor neuron facial palsy, with contralateral hemiplegia (arm leg trunk). The limb paralysis recovers because most of the descending motor fibers are ventral to the infarct.
Dejerine's syndrome
Also callled medial medullary syndrome this is characterized by a lesion in the anterior spinal or paramedian branches of the vertebral artery, results in a loss of conscious proprioception, touch, and pressure contralateral, contraleteral UMN paralysis, paralysis of ipsilateral tongue and ipsilateral deviation upon protrusion
Cranial nerves arise from _____ and placodes (optic and otic) of the developing brain.
Neural crest cells
_____ motor and sensory neurons arise from neuron populations found in region between alar plate and the basal plate just deep to the sulcus limitans.
Autonomic
The migration of neuron populations in the brainstem is called _____; it establishes the branchiomotor neuron populations that are associated with CNs V,VII, IX and X.
Neurobiotaxis
Special visceral efferent components control:
SVE = SSE - Special somatic efferent - in some textbooks of neuroanatomy
Skeletal muscle derived from branchial arches (branchiomotor)
1. The GVE (visceromotor) component of CN III is from the _____ nucleus (accessory oculomotor nuc.) in the _____ of the midbrain. *Supplies Sphincter ciliary m. of eye
3. All components of CN III exit from the brainstem into the _____ (cistern)
1. Edinger-Westphal
2. Periaqueductal gray
3. Interpeduncular fossa
Horner's Syndrome
Horner's syndrome includes miosis - reduction in pupil diameter due to unopposed action of parasympathetic innervation; ptosis - drooping of the eyelid due to loss of the innervation to superior tarsal muscle; enophthalmos - apparent sinking of eyeball in socket because of the interrupted innervation; and anhidrosis - lack of sweating on the affected side.
CN III also innervates the levator palpebrae superioris m. (upper bank of m. fibers). Lower bank of m. by _____ from _____. (Horner's syndrome)
1. Postganglionic sympathetics
2. Superior cervical ganglion
1. SSA= Special somatic afferent components
(Special sensory); deals with what 2 senses?
2. SVA= Special visceral afferent components
(Special sensory); deals with what 2 senses?
1. Vestibular function and hearing
2. Taste and olfaction
1. 3 Disorders involving CN III:
2. CN III palsy - 3 clinical signs
1. Diabetes
2. Uncal (temporal lobe) herniation
3. Berry aneurysms

4. Eyeball abducted and depressed - LR and SO
5. Pupil dilated - dilator pupillae (sympathetic innervation)
6. Eyelid ptosis - drooping eyelid; no LPS
What is affected directly below the tentorium cerebelli?
Tectum of midbrain and CN IV
****TQ
Head trauma (though rare)
CN IV Impacts the incisura of the tentorium cerebelli
Tentorium cerebelli
CN IV Palsy
Diplopia (double vision) when attempting to look "down and in" e.g., reading a newspaper. One can not fully depress the eye when the eyeball is adducted, because of the sup. ob. m. weakness
Head-tilt is a compensatory finding
A lesion of the CN VI nucleus causes?
Simultaneous ipsilateral CN VI and contralateral CN III palsies, because the interneurons of the medial longitudinal faciculus (MLF) from the center for horizontal gaze in the pons are also interrupted.
CN VI palsy - clinical sign
CN VI palsy - clinical sign
Eyeball is adducted and can not be rotated laterally past the mid-position of gaze.
The spinal nucleus of CN V, containing the 2nd order neurons, underlies the spinal tract of CN V and projects its axons via the ventral trigeminothalamic tract _____ to the ventral posterior medial nucleus (VPM) of the thalamus.
Contralaterally
Ventral Posterior Medial (VPM) neurons (3rd order, in Thalamus) project their axons via the _____ to the primary and secondary sensory cortices (Parietal lobe = sensory).
Posterior limb of the internal capsule
A homolateral lesion in the brainstem which encompasses both the spinal tract of CN V and the spinothalamic tract (ALS) produces signs of?
alternating analgesia i.e., ipsilateral hemifacial analgesia combined with contralateral body (limb and truncal) analgesia.
Nerve to the stapedius m. is given off of Facial n. CN VII while nerve travels through the facial canal. Stapedial m. contraction dampens the oscillations of the stapes. Dysfunction results in _____.
Hyperacusia
(N122) CN VII SVE (branchiomotor) component
Origin: Facial nuc. (pons)
1. Exits brainstem at inferior pontine sulcus
2. Joins CN VIII and enters the _____ of the petrous temporal bone.
3. Traverses _____ and exits the skull at the stylomastoid foramen -> divides to supply the mus. of facial expression.
Nerve to the stapedius m. is given off while nerve travels through the facial canal. Stapedial m. contraction dampens the oscillations of the stapes. Dysfunction results in hyperacusia.
1. Inferior pontine sulcus
2. Internal acoustic meatus
3. Facial canal
(N122) CN VII GVE (visceromotor for lacrimation)
1. Origin:
2. Exits brainstem as the "nervus intermedius" at inferior pontine sulcus.
3. Enters _____ and facial canal. It is the first component to branch from the bundle of CN VII fibers.
4. Forms the _____
Exits the temporal bone at the hiatus for the greater petrosal n. (lat. aspect of petrous ridge)
5. Takes an epidural course medially and inferiorly, and traverses obliquely the _____ at the base of the skull.
6. Enters the _____ of the sphenoid bone (N. of the pterygoid canal or Vidian n.)
7. Synapses with the post. gang. para. sympathic neurons in the _____ ganglion located in fossa of the same name.
8. Post. gang. parasympathetics enter the orbit through the _____, join CN V2, and course with its zygomatic br. to the lacrimal gland.
9. Dysfunction:
1. Superior salivatory nucleus (lacrimal nucleus) in pons
2. Nervus intermedius
3. Internal acoustic meatus
4. Greater (superficial) petrosal n.
5. Foramen lacerum
6. Pterygoid canal
7. Pterygopalatine ganglion
8. Inferior orbital fissure
9. Conjunctivitis
What nerve provides preganglionic parasympathetic innervation to the submandibular ganglion?
Chorda tympani n.
(N122) CN VII GVE (visceromotor for salivation)
1. Origin: _____
2. Exits brainstem as the "_____" at inferior pontine sulcus.
Enters internal acoustic meatus and facial canal along with CN VIII.
3. Branches from the bundle of CN VII fibers and forms the _____
Crosses the manubrium (handle) of the malleus and tympanum, hence the name, chorda tympani n.
4. Exits the temporal bone at the _____ behind the mandibular fossa.
5. Joins the _____
6. Synapses in the submandibular ganglion
Post. gang. parasympathetics from the ganglion supply innervation to the submandibular and sublingual salivary glands
1. Superior salivatory nucleus (lacrimal nucleus) in pons
2. Nervus intermedius
3. Chorda tympani n.
4. Petrotympanic fissure
5. Lingual n. (V3)
6. Submandibular ganglion
(N122) SVA (special sensory) component of CN VII
1. The taste neurons have cell bodies located within the _____ ganglion located within "the bend" of the canal, hence the name.
2. The central processes of the ganglion cells exit the petrous portion of the temporal bone via the _____ and form a part of the nervus intermedius of CN VII.
3. Upon entering the brainstem, the central processes form the _____ and eventually terminate by synapsing with neurons in the _____.
1. Geniculate ganglion
2. Internal acoustic meatus
3. Tractus solitarius
4. Nucleus solitarius
1. Nucleus solitarius projects to the parabranchial nucleus and Ventral Posterior Medial (VPM) nuc of the thalamus via the _____.
2. Interpretation of taste sensation is thought to occur at the level of the opercular, frontal and anterior portion of the _____.
1. Central tegmental tract
2. Insular cortex
What nerve innervates the carotid body (chemoreceptor) and the baroreceptors of the carotid sinus.
CN IX - Glossopharyngeal
(N124) CN IX - SVE (branchiomotor) component
1. Origin:
2. Exits brainstem at the _____
3. Exits skull through the _____
4. Innervates the _____ m. (derived from the 3rd arch)
1. Nucleus ambiguus (medulla)
2. Postolivary sulcus
3. Jugular foramen
4. Stylopharyngeus m.
(N124) CN IX - GSA (somatic sensory) component
Pain & temp receptors->jugular ganglion
1. Axons from ganglion cells enter the skull through the _____
2. Fibers enter brainstem at the _____, form the spinal tract of CN V, and synapse with neurons in the underlying _____.
1. Jugular foramen
2. Postolivary sulcus
3. Spinal nucleus of CN V
(N124) CN IX - GVA (visceral sensory) component
Origin: Baroreceptors of the carotid sinus => carotid sinus n. (Hering's n.) => jugular ganglion
Axons from the ganglion cells enter the skull through the jugular foramen and enter the brainstem at the post-olivary sulcus.
The axons synapse with neurons of the _____.
Nucleus solitarius
(N124) CN IX - GVE (visceromotor) component - Tympanic
1. Origin:
Exits brainstem at the post-olivary sulcus
Exits the skull through the jugular foramen
2. A recurrent branch re-enters the petrous temporal bone as the _____ and contributes to the formation of the tympanic plexus of nerves.
3. Outflow from the plexus continues as the _____ and exits the temporal bone via a hiatus named for the nerve.
1. Inferior salivatory nucleus (preganglionic parasympathetic nucleus)
2. Tympanic n. of Jacobson
3. Lesser petrosal n.
(N124) CN IX - GVE (visceromotor) - Parotid gland
Exits the middle cranial fossa by descending into the infratemporal fossa through the foramen ovale or foramen innominata.
1. The lesser petrosal n. terminates by synapsing in the ____ ganglion.
2. Postganglionic parasympathetic fibers utilize the _____ br. of CN V to access the parotid gland.
1. Otic ganglion
2. Auriculotemporal
(N124) CN IX - SVA (special sensory) component
Taste receptors post. 1/3rd of tongue (circumvallate papillae) => pharyngeal plexus of nn. => jugular ganglion => fibers enter the skull through the jugular foramen and form the tractus solitarius.
The axons will also synapse with neurons of the _____.
Nucleus solitarius
(N125) CN X - SVE (branchiomotor) component
1. Origin:
2. Exits brainstem at the _____.
3. Exits skull through the _____.
Innervates the soft palate, pharyngeal constrictor mm. and the muscles of the larynx.
1. Nucleus ambiguus (medulla)
2. Postolivary sulcus
3. Jugular foramen
(N125) CN X - GVE (visceromotor) components - Heart & Gut
1. Origins:
Nucleus ambiguus is primarily the branchiomotor nucleus for CNs IX, X and XI.
Fibers exit the brainstem at the postolivary sulcus.
Fibers exit the skull through the jugular foramen.
2. Innervates Meissner's plexus and Auerbach's myenteric plexus in the gut, or the SA node of the heart. (stimulation -> _____)
1. Dorsal motor nucleus of vagus (gut) and Preganglionic parasympathetic part of Nucleus ambiguus to heart
2. Bradycardia
Disorders of CN X
Vasovagal syncope (causes what?)
Tumors (what and where?)
Trauma
- Cervical injuries
- Surgical trauma (thyroidectomy, repair of a ductus arteriosus )
- Paralysis of soft palate
- Uvula deviates _____ the side affected
- Paralysis of the muscles of the larynx
- Stridor of voice
1. Bradycardia and low BP
2. Glomus jugulare at jugular foramen
3. Opposite
(N126) CN XI - GSE (somatic motor) component
1. Origin:
2. Motor fibers ascend and enter the skull through the _____.
3. Fibers converge with the bulbar fibers issuing from the caudal aspect of the post -olivary sulcus and exit the skull through the _____.
1. Accessory nucleus of upper 5/6 cervical cord segments
2. Foramen magnum
3. Jugular foramen
Disorders involving CN XI
Trauma to neck
CN XI palsy
- Shoulder droop with inability to shrug the shoulder.
- Inability to rotate the head against resistance to the side _____ the injured nerve.
Opposite
(N126) CN XI - SVE (branchiomotor) component
1. Origin:
2. Exit brainstem at the post olivary sulcus
Distributed with CN X to musculature of the _____.
1. Nucleus ambiguus
2. Larynx
(N127) CN XII
1. Crosses both carotids 1 cm above common carotid bifurcation that occurs at cervical level, __.
Supplies all the "glossus" mm with the possible exception of the palatoglossus m.
Genioglossus m. - most clinically important muscle. Lower motor neuron lesions of CN XII causes deviation of the tongue to the affected side.
2. Upper motor neuron lesions, according to some authors, result in deviation of the tongue to the side _____ the UMN defect.
1. C3
2. Opposite
(N127) CN XII
GSE (somatic motor ) component
1. Origin:
2. Intrafascicular course in the brainstem carries CN XII in close association to the _____ and _____.
Exits brainstem at the pre-olivary sulcus
Exits skull through the hypoglossal canal
1. Hypoglossal nucleus (medulla)
2. Medial lemniscus and pyramids