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Bio 669 Quiz 2 Exam Questions And Answers
(Guaranteed A+)
Neuron is composed of - answer✔cell body, dendrites, axon
densely packed cell bodies in the CNS are called _____ - answer✔nuclei
densely packed cell bodies in the PNS are called _____ - answer✔Ganglia
What are dendrites? - answer✔Receptive portions of the neuron; receives information
What do axons do? - answer✔Carry impulses away from the cell body
is membrane potential about the inside of the cell or the outside? - answer✔inside of the cell
what is an electrochemical gradient? - answer✔describes the forces affect on ion movement if
allowed to become permeable a membrane
when does action potential start? - answer✔when a membrane is depolarized enough that it
triggers voltage-gated ion channels
What is a graded potential? - answer✔changes in membrane potential that decreases over
distance
what Is a refectory period? - answer✔a period immediately following stimulation that is
unresponsive for some time.
Reduced sensitivity
What is myelin? - answer✔A segmented layer of lipid material, acts as insulation.
what is myelin called in the PNS? - answer✔Schwann cells
What are the nodes of Ranvier? - answer✔gaps/regular interruptions in the myelin sheath
What is saltatory conduction? - answer✔The flow of ions between segments of myelin rather
than alone the entire length of the axon. Like playing leap frog.
What is divergence? - answer✔ability of branching axons to influence many neurons
What is convergence? - answer✔Branches of numerous neurons converging on one or a few
neurons
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