Neurons, Synapses, and Signaling Part 3

Question 1

In vertebrates, axons are insulated by a
myelin sheath,

Answer 1

which enables fast conduction
of action potentials

Question 2

Myelin sheaths are produced by

Answer 2

glia—
oligodendrocytes in the CNS
AND
Schwann
cells in the PNS

Question 3

action potentials are formed only at

Answer 3

nodes of Ranvier

Question 4

What are nodes of Ranvier?

Answer 4

gaps in the myelin sheath where voltage-gated Na+ channels are found

Question 5

action potentials in myelinated axons jump between the
nodes of Ranvier in a process

Answer 5

saltatory conduction

Question 6

Selective advantage of myelination is space efficiency

Answer 6

space efficiency

Question 7

How is information transmitted

Answer 7

via synapses

Question 8

Chemical synapses ( most synapses are this) are when

Answer 8

chemical
neurotransmitter carries information
from the presynaptic neuron to the postsynaptic cell

Question 9

What does a presynaptic neuron do

Answer 9

synthesizes
and packages neurotransmitter in synaptic vessicles located in synaptic terminal

Question 10

arrival of the action potential

Answer 10

causes the release of the neurotransmitter

Question 11

The neurotransmitter diffuses across the____ and is received by the____. Neurotransmitter molecules must then be cleared from the synaptic cleft.

Answer 11

synaptic cleft
postsynaptic cell