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Samsam Anatomy Test 5 - NERVOUS SYSTEM

Terms in this set (84)

function of nervous system
control the function of the body; composed of specialized cell with three overlapping functions: receives inputs from outside and inside body, processes and interprets sensory input, dictates a response by activating effector organs
central nervous system
brainstem and spinal cord
peripheral nervous system
everything else nerve related (including cranial nerves)
cerebral meninges
both brian and spinal cord are covered by; dura, arachnoid, and pia maters
cerebrospinal fluid (CSF)
brain and spinal cord are suspended in it; in subarachnoid space
ventricles
hollow spaces in brain filled with CFS; 50-150cm water pressure, transparent
corra plexus
in arachnoid matter, CSF produced by capillaries
dura venous sinuses
receives all cerebral veins and CSF from arachnoid granulations
neurons
transmit electrical signals, found in grey matter of CNS and ganglia
neuroglial cells (support cells)
nonexcitable, surround and wrap neurons
astrocytes
most abundant glial cell type; take up and release ions to control the environment around neurons; recapture and recycle neurotransmitters
microglia
smallest and least abundant; phagocytes; macrophages of the CNS
ependymal cells
line the central cavity of the spinal cord and brain
oligodendrocytes
produce myelin sheaths in CNS
satellite cells
(PNS) surround neuron cell bodies within ganglia
schwann cells
(PNS) surround axons in the PNS; form myelin sheath around axons of the PNS
nerve impulse
generated at the initial segment of the axon and conducted along the axon; releases neurotransmitters at axon terminals
neurotransmitters
excite or inhibit neurons
synapses
site at which neurons communicate, signals pass across synapse in one direction
presynaptic neuron
conducts signal toward a synapse
postsynaptic neuron
transmits electrical activity away from a synapse
action potential
strong stimulus applied to the axon triggers; membrane becomes negative externally; impulse travels the length of the axon, membrane depolarizes itself
excitatory synapses
depolarizes the postsynaptic membrane
inhibitory synapses
reduces the ability of the postsynaptic neuron to generate an action potential
endoneurium
allayer of delicate connective tissue surrounding the axon
nerve fascicles
groups of axons bound into bundles
perineurium
connective tissue wrapping surrounding a nerve fascicle
epineurium
whole nerve is surrounded by tough fibrous sheath
spinal cord
is covered by meninges and is suspended in the CSF
sensory (afferent) signals
picked up by sensor receptors; carried by nerve fibers of PNS to the CNS
motor (efferent) signals
carried away from the CNS; innervate muscles and glands
reflex arcs
simple chains of neurons; explain reflex behaviors, determine structural plan of the nervous system, responsible for reflexes, rapid autonomic motor responses, can be visceral or somatic
five essential components of the reflex arc
receptor, sensory neuron, integration center, motor neuron, effector
receptor
site where stimulus acts
sensory neuron
transmits afferent impulses tot he CNS
integration center
consists of one or more synapses in the CNS
motor neuron
conducts efferent impulses from integration center to an effector
effector
muscle or gland cell; responds to efferent impulses, contraction or secreting
monosynaptic reflex
simplest of all, just one synapse, fastest, knee-jerk
polysynaptic
more common; single interneuron between sensory and motor neuron, withdrawal
parts of brain
cerebral hemispheres, diencephalon, brain stem, cerebellum
brian stem
includes the midbrain, pons, and medulla oblongata, several general functions: produces automatic behaviors necessary for survival, 10 of the 12 pairs of CN attatched
CN 4
only nerve on brainstem you can see leaving on the posterior aspect
thalamus
main sensory life center of the brain
cerebellum
located dorsal to the pons and medulla, smoothes and coordinates body movements, helps maintain equilibrium
folia
surface folded into ridges
intention tremour
sign of cerebella damage/falls on site on damage (right side damaged, fall to the right)
central sulcus
frontal and parietal lobe separated by
gyri (grooves)
create larger areas for nerves to be for more functions
precentral gyrus
most motor activity we do
transverse fissue
separates cerebrum and cerebellum
longitudinal fissure
separates cerebral hemispheres
sulcus
grooves on the surface of the cerebral hemisphere
cerebral cortex
home of conscious mind, enables us to be aware of ourselves and sensations; initiate and control voluntary movements, communicate, remember, and understand composed of gray matter
Broca's area
44-45 Brodmann areas, speech motor area (left hemisphere often dominant)
motor effasia
can't talk but can write
fluent (sensory effasia)
can talk but isn't make real words or coherent sentences
area 17
primary visual area
primary motor cortex
controls motor functions; located in precentral gyrus (brodmann area 4)
pyramidal cells
large neurons of primary motor cortex
contralateral
pyramidal axon cross over to opposite side of brain
motor homunculus
body map of the motor cortex
somatotopy
body is represented spatially in many parts of the CNS
sensory areas
cortical areas involved in conscious awareness of sensation; located in parietal, temporal and occipital lobes; brodmann areas 1-3, projection is contralateral
somatosensory association area
lies poserior to the primary somatosensory cortex, brodmann areas 5 and 6, ingrates different sensory inputs: touch, pressure; draws upon stored memories of past sensory experiences
basal nuclei
grey areas in the white matter of the brain and contain neurons: caudate neucleas, lentiform nuclei, amygdala; cooperate with the cerebral cortex in controlling movements
corpus striatum
is situated lateral to the thalamus, divided by a band of nerve fibers called the interal capsule, into the caudate nucleus and the lentiform nucleus
lentiform nucleus
composed of the globus pallidus and putamen
lateral ventricles
located in cerebral hemispheres, horseshoe shape
third ventricle
lies in diencephalon, connected with lateral ventricles by inter ventricular foramen of Monro
fourth ventricle
lies in hindbrain, connects to the central canal of the spinal cord; apertures helps get CSF into subarachnoid space
cerebral aqueduct of Sylvius
connects 3rd and 4th ventricles
sensory
olfactory nerve
sensory
optic nerve
motor
oculomotor nerve
motor
trochlear nerve
sensory and motor
trigeminal
motor
abducent nerve
sensory and motor
facial nerve
sensory
vestibulocochlear nerve
sensory and motor
glossopharyngeal nerve
sensory and motor
vagus nerve
motor
accessory nerve
motor
hypoglossal nerve
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