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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 |