Exam 4 brain and spinal cord

3 lbs.
Gyrus or convulsion
Folds in the brain
Shallow area
Deep area
Longitudinal fissure
Separates into left and right hemispheres, connected by the corpus callosum
Central sulcus
Coronal plane (frontal from parietal)
transverse fissure
cerebrum and cerebellum
lateral fissure
separates temporal lobe
cerebral cortex
the surface of the brain. Consists of gray matter. 75% of cell bodies
frontal lobe
anterior to central sulcus
consists of three sections. Prefrontal lobe, premoter area, and precentral gyrus
prefrontal lobe
analysis , reasoning, emotions, behavior, personality, judgement
precentral gyrus
voluntary muscle actions
begins motor impulses
-left controls right side of body and vice versa
premotor area
broca's area (language and speech)
organization of groups of muscles, largely automatic eye and writing
Parietal Lobe
behind central sulcus
post central gyrus
parietal lobe
senses of temperature, touch, pressure, pain, muscle and position and some taste
wernicki\e's area (interp. of speech)
Temporal lobe
below lateral fissure
Hearing and smell interp.
learning and memory ( with hippocampus)
occipital lobe
sense of vision
mamillary bodies
relays limbic (sleep) and memory
olfactory bulb
interprets smell.
Under frontal lobe
association areas
50% of cortex
General interpretations and complex memories.
thinking, memorization. Basically associating information.
White matter of the cerebrum
commisural fibers
projection fibers
association fibers
basal nuclei or ganglia
commisural fibers
between hemispheres through corpus callosum(bridge)
corpus callosum
connecting the left and right hemispheres
projection fibers
brain talking to the rest of the body
(up and down)
association fibers
communication within the same hemisphere
basal nuclei (ganglia)
gray areas (muscle coordination)
gray areas
limbic system (Behavior)- memory (also the fear center for ptsd
limbic system
input for hypothalamus
major memory relay center
Automatic reflex (not so much thinking)
consists of the Diencephalon (thalamus and hypothalamus), midbrain, pons, medulla oblongata
sensory relay center (gateway to the cortex)
crude sensation
relaying information to the specific lobe
parts of the thalamus
medial geniculate body- hearing
lateral geniculate body- vision
pineal gland
roof of thalamus
area for melatonin
input and output center
cardiac and vasomotor center (bp and heart reg), body temp., hunger and satiety, control asn, control pituitary (hormones), emotions (sex drive), RAS system, body fluid balance, SCN (biological clock
(3 & 4 cranial nerves)
main motor pathway- reflexes for equilibrium and posture
(5,6,7,8 cranial nerves) BRIDGE
respiratory centers
relays to cerebellum
medulla oblongata
(9,10,11,12 cranial nerves)
cardiac, vasomotor, respiratory centers
cough, sneeze and swallow reflex
crossing over of motor fibers
miniature brain
consists of purkinje cells and the arbor vitae(tree of life)
functions: equilibrium, coordination, position, muscle tone, plans and predicts movements, monitors and mediates reflexes, input from cerebrum, evaluates performance
membrane covering brain and spinal cord (CNS)
contains the dura mater, arachnoid, and pia mater
dura mater
connective tissue
outer most layer (protective membrane)
epidural and subdural space
extensions of CSF
vill into dura mater into venous sinuses where CSF enters blood
arachnoid villi is the exit for the fluid
pia mater
right on the surface of the brain and spinal cord
blood vessels-become choroid plexus) its kind of like ceran wrap
cerebrospinal fluid
60-150 ml presents but 500 ml made per day
colorless- protection and transport, stable ionic balance
cavities in the brain for CSF
there are four
first and second- choroid plexus (70%of CSF)
then through the inter ventricular foramen to the the third ventricle- choroid plexus where CSF is made by Ependymal cells. Then through the cerebral aqueduct to the fourth ventricle. It then circulates from ventricles to other foramen to arachnoid layer to the central canal
special systems
RAS- reticular activating system
Limbic system
continuous impulse- maintains muscle tone and posture
(reflex control) alertness, filter for sensory information, modulates pain
your wake alert system-allows you to concentrate on one thing at a time
Limbic System
emotions and behavior
hypothalamus -cerebrum,hippocampus, and amygdala
special systems structure
gray matter inside and white matter outside and continues down the spinal cord.
2 types of cells in nerve tissue
glia and neuron
2 parts of the cerebrum
cerebral cortex and white matter
the base nuclei functional in memory are
amygdala and hippocampus
a wrinkle or fold in the cerebrum
white matter contains 2 areas
basal ganglia and tracts
the outer mm's of the cerebrum is
the gray areas in the white matter of the cerbrum
basal ganglia
what speech area is in the parietal lobe
wernicke's area
which part of the brain controls body fluid balance
the descending motor fibers for muscle movement cross over in the
medulla oblongata
what part of the brain controls pituitary gland
the sensory relay center
2 areas for respiritory
pons and medulla
2 areas have cardiac and vasomotor centers
hypothalamus and medulla
where are sensory impulses relayed to
which part of the brainstem that controls balance and position
which part of the brainstem is known as middle management
cerebellum (its the input of the cerebrum)
Peripheral Nervous System
cranial nerves
bundles of neurons(axons) enveloped by membranes
what are the membranes in nerves
what type are nerves in the PNS
motor, sensory or mixed
how many cranial nerves are there
1st cranial nerve
Olfactory- Smell
2nd Cranial nerve
Optic- Vision
3rd cranial nerve
Oculomotor- moves the eye and lid
constricts and dilates pupil and adjusts lens
4th cranial nerve
trochlear- moves the eye
5th cranial nerve
trigeminal- sensations of the face and taste
muscles for chewing
6th cranial nerve
abducens- moves eye
7th cranial nerve
Facial- for taste, facial expression muscles, for salivary and lacrimal glands (crying, drooling smiling and tasting)
8th cranial nerve
auditory- (vestibulochlear) hearing and balance
9th cranial nerve
glossopharyngeal- for tastes, move the tongue to swallow (salivary gland)
10 cranial nerve
Vagus- taste, speaking and swallowing muscles, major nerve of the parasympathetic system. and longest cranial nerve
11th cranial nerve
accessory- motor to muscles and neck
12th cranial nerve
Hypoglossal- move the tongue and swallow
central nervous system
spinal cord
three main functions of the spinal cord
pathway for motor and sensory information
site for spinal reflexes
contains the center of walking
structure of the spinal cord
extends to second lumbar vertebrae
gray matter is called horns
white matter is called columns (myelinated)
three ascending tracts of the spinal cord
two descending tracts of the spinal cord
cuneate tract
position and touch
pain and temp
sense of position and muscles (sensations)
movement of skeletal muscles
involuntary muscle tone and posture- maintain balance
how many spinal nerves are there
and sacral 6
a collection of nerves
the nerve in the cervical plexus
phrenic nerve (breathing nerve)
nerve in the sacral plexus
sciatic nerve (largest nerve in the body)
plexus for the arm
cauda equina
known as the horse tail
ends of spinal nerves below the cord
it hangs of the end of the spinal cord
two roots in the cord
dorsal root- SENSORY
ventral root- MOTOR
branches of spinal nerves
posterior ramus
branch to back of body
anterior ramus
branch to front of body
somatic reflex
(spinal reflex)
a stimulated response (not thinking reflex)
receptor in muscle to dendrite of sensory neuron to dorsal root to cell body to axon of sensory neuron to spinal cord interneuron to dendrite to cellbody of motor neuron to axon of motor neuron to ventral root to muscle
Autonomic system
the motor system coming down from the brain.
self controlled reflexes. Involuntary impulses to smooth and maintains homeostatis
2 neurons in the autonomic system
preganglionic and postganglionic
rami (circuits) in the autonomic systems
go into or out of ganglion (neurons can synapse, converge or diverge)
2 divisions of the autonomic system
replenishes body supplies, conserves energy
cranial nerves- 3,7,9,10 (90% is VAGUS)
function- slow heart rate down, slow breathing down, stimulates digestive system, stimulates urinary system, constricts pupil in the eye. stimulates more liquid from the salivary glands and constricts airways
the neurotransmitter for the parasympathetic system
the neurotransmitter for the sympathetic division
sympathetic system
stress, 'flight or flee'
all gear for emergency (middle part of the spinal cord)
function-speeds up heart rate, stimulates breathing, inhibit digestive system, inhibits urinary system, dilates pupil of the eye, produces liquid with mucus saliva in the salivary gland, raise blood pressure but will stop sending signals to stop as well, sweat is stimulated, adrenal gland is stimulated (adreniline) dilates air way (pulls air in)
specialized neurons (each sense has a special receptor)- changes a stimulus into a nerve impulse called TRANSDUCTION
senses generates a
receptor potential
eye receptors
eye external anatomy
protection is blinking reflex,corneal reflex, eyelid
conjunctiva- mucous membrane (very thin on cornea) transparent (allows light through
lacrimal glands-produces tears
lysozymes- drains in duct in lacrimal bone (keep eye lubricated prevents infections by each enzyme)
three layers of wall of the eye
dense fibrous connective tissue, blood vessels and nerves (gives it shape)
CORNEA- becomes clear
contains melanin and blood vessels
CILIARY BODY(muscle- attached to LENS by suspensory ligaments also makes aqueduct humor
controls lens of eye
consists of the IRIS and PUPIL
rods and cones (receptors for vision
BLIND SPOT- where the optic nerve enters (no receptor there)
FOVEA CENTRALIS- allows for the clearest vision (has most of the cones) there are more rods than cones. Rods are the night vision for black and white. Cones are for the day vision for red green and blue.
color blindness
messed up cones
vitamin A
good for the cones in the eye
Anterior and Posterior chamber
contains aqueduct humor (clear fluid in front of the eyes has slow circulation and is made by the ciliary body and drains out the CANAL of SCHLEMM
suspensory ligaments. Helps focus the light on the retina. Its flexible and has the an automatic reflex. ligament relax the lens becomes more convex has close vision and opposite for far vision
Vitreous humor
for the shape, gel (its like jello but clear) does not circulate.
4 factors for normal vision
1)refraction-bending the light rays, focuses,reduces and inverts. Cornea is main refractor, lens fine tunes
2)accommodation-ability to focus at different distances. LENS and SYMPATHETIC-for far visions and PARASYMPATHETIC for near vision
3)constriction and dilation of pupil (Iris part ANS)
4)Convergence-both ees same view and eye muscles
taste receptors
Taste sense
adaption (can raise threshold)
taste buds are the receptors
receptors distinguish sweet, salty, sour, bitter, and umami (meaty)
smell receptor
smell sense
adaption (can raise threshold)
olfactory epithelium is the receptor
at the top of the nasal cavity
Touch receptor
Touch sense
adaption (can raise threshold)
meissners corpuscle are the receptors
found really close to the epidermis
pressure receptor
pressure sense
pacinian corpuscles are the receptors
found deep in the dermis
Pain receptors
pain sense
free nerve endings are the receptors
can respond to more than one stimulus
stimuli: chemical, mechanical, thermal, plymodal
bradykinin-chemical in body that stimulates pain receptors
stimulus will still control
receptors are found in the skin but inside the body as well
temperature receptors
temperature sense
adaption (can raise threshold)
found in the skin by fee nerve ending that distinguishes cold and hot
position receptors
position sense
receptors for muscles are the muscle spindles. muscle length, body movements (to cerebellum)
receptors for tendons and ligaments are the Golgi tendon organs and they cause tension
spinal reflex
begins at the receptor. The impulse travels through the dendrites to the dorsal root to the cell body into the sensory neuron in the spinal cord. It synaspes in the gray matter with a dendrite and cell body then synaspes with an axon of the motor neuron. The impulse goes out the ventral root to the muscle.
where are the tracts located in the spinal cord
the white matter
name the 3 layers of the meninges in order from the brain to the bone
pia mater-arachnoid- dura mater
a collection of axons and dendrites wrapped with connective tissue
a nerve
spinal cord starts and ends and is called a what
starts at the medulla ends at L2 and cauda equina
where is the choroid plexus located
in the ventricles
how does CSF get from lateral ventricles to the third ventricle?
inter ventricular foramen
what are the functions of CSF
protection, transport and waste
the cranial nerves that are only motor
the cranial nerves that are only sensory
which cranial nerves are mixed
where is the epidural space located
above the dura mater
the subdural space is located
the pia mater
what does the pia mater contain
blood vessels and found under the arachnoid mater
where does the CSF reenter the blood
arachnoid villi
what is contained in the arachnoid layer
light can bend
2 ear receptors
Hair cells and
Organ of Corti
All responds by movement of fluid