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ITM misc. info
nervous system
Question | Answer |
---|---|
peripheral nervous systemPNS | comprised of cranial & spinal nerves that exit from brain & spinal cord |
cranial nerves | 12 pairs emerge from brain |
spinal nerves | 31 pairs exit spinal cord thru intervertebral foramina |
PNS | subdivided into autonomic & somatic nervous systems |
somatic | voluntary system transmits impulses from CNS to skeletal-makes us move |
autonomic | involuntary nervous system innervates smooth muscle, cardiac muscle & galnds |
autonomic subdivisions | sympathetic & parasympathetic |
sympathetic | fight or flight-speeds up heart rate |
parasympathetic | rest & digest-slows heart rate |
sensory | conduct signals to CNS |
motor | carry signals from CNS |
oligodendroglia | forms myelin sheath in CNS |
schwann cells | in PNS |
refractory period | very brief period after inhibition when neuron recovers |
absolute refractory period | time during which neuron will not respond to any stimuli-beginning of depolization |
relative refractory perion | when neuron will onlyrespond to a very strong stimuli-end of depolarization |
neurotransmitters | chemical compounds released by vesicles, many are also hormones |
cerebrum | higher function, makes us human |
cerebellum | movement, coordination |
spinal cord | composed of white & gray matter |
white matter | axons |
gray matter | cell body |
lower motor neurons | flaccid |
upper motor neurons | spastic |
upper | CNS |
lower | peripheral |
subdural hematome | bleeding between dura & arachnoid |
epidural hematoma | bleeding between skull & dura |
endoneurium | surrounds each nerve fibers |
perineurium | surrounds each fascicle |
fascicle | group of nerve fibers |
epineurium | surrounds the nerve |
dura mate-outermost covering | tough, white fibrus connective tissue |
dura mater | tough mother |
dura mater | protects CNS from being damaged by skull & spine |
arachnoid-middle layer | cobweb like membrane, contains many blood vessels |
pia mater-inner layer | very thin, tight fitting cover contains blood vessels to nourish verve tissue |
pia mater | adheres directly to brain & spinal cord |