nervous system Flashcards
(30 cards)
sensory afferent division
conveys impulses TO the cns
motor efferent division
carries impulses FROM the cns to viscera or muscles glands
neuroglia
“nerve glue” support insulate and protect delicate neurons
Astrocytes
anchors neurons to nutrient supply lines, numerous.
microglia
phagocyes that dispose of debris
ependymal cells
line cavities of brain and spinal cord. circulates Cerebrospinal fluid
Oligodendrocytes
produce myelin sheaths. cant transmit nerve pulses
axons
conduct nerve impulses away from the cell body
association neurons (interneurons)
connect the motor and sesory neurons in neural pathways
multipolar neuron
multiple number of processses extending from the cell body
bipolar neurons
rare in adults, found in special sense organs, receptor cells
unipolar neurons
single process from cell body very short
action potential (never impulse)
an activated long distance signal
depolarization
more possitive ions on the outter face than on the inner changes polarity of the membrane
polarized
fewer positive ions on the inner face of the membrane than on the outside
repolarization
outflow of possitive ions from the cell restoring to polarized (resting) stage
cerebral hemispheres
most superior part of the brain
neural tube
devoping CNS in an embryo
ganglia
small collections of cell bodies found outside the CNS in the PNS
schwan cells
form the myelin sheaths
sensory input
where stimuli is gathered
integration
where the decision on what to do is made
motor output
the response by muscles or glands
reflex arcs
reflex that occurs over neural pathways
