CH20 Flashcards
PERIPHERAL nervous system include sensory and motor neurons whereby
sensory=___
motor=___
afferent, efferent
sensory, afferent fibers transmit….
transmit impulses from receptors to CNS
sensation, blood and lymph vessels, skin, muscles, tendons, mechanorecptors, proprioceptors are
afferent fibers
transmit impulses from CNS to effector organs are ___ and results in muscle conraction and reflex activity
motor division efferent fibers
responsible for maintaining internal environment
autonomic nervous system
releases noreipinephrine and excites an effctor organ and inc heart rate or BP
sympathetic division of ANS
releases ach and inhibits effctor organ
parasympathetic division of ANS
cell body=
soma
receptor areas, conduct impulses toward cell body
dendrites
carries electrical impulse away from cell body toward another neuron ; may be covered by schwann cells
axon nerve fiber
forms discontinuous myelin sheath along length of axon (insulation)
schwann cells on nerve fibers
nerve impulses is propagated bounces from node to node; saltatory conduction- increases conduction velocity
gaps-nodes of ranvier
large myelinated fibers- skeletal muscle 60-100 m/sec
axon nerve fiber
non-myelinated fibers mixed in with myelinated 6-10m/sec
axon nerve fiber
ability to repsond to a stimulus and convert it to a neural impulse
irritability
transmission of the impulse along the axon
conductivity
- at rest, neurons are negatively charged inside
- determined by concentration of ions across membrane
resting membrane potential
-negative charges inside cell are anions
-proteins, phosphate groups and nucleotides
-attract postively charged ions ECF
-positively charged outside cell in relation to inside
with most important being __.__.and ___
Na, K, Cl
difference in ion sset up otential difference across membrane and are controlled by
voltage controlled gates
resting membrane becomes less negative and more toward threshold, movement of sodium into cell , so becomes postive inside
depolarization of AP
stimulus stops, gates of Na close and and K+ gates open; resting membrane potential restored
repolarization
contact points between axon of one neuron and dentrite of another neuron
synapse
other terms used for synapse
neuromuscular junction, myoneural junction, and motor end plate
- causes depolarization which may ormay not reach threshold;
- sufficient amounts of NT causes depolarization to threshold
- AP is generated
excitatory postsynatpic potentials [EPSP]
