11.3 – The nerve muscle relationship

Question 1

what is a motor unit?

Answer 1

all of the muscle fibers innervated by a single motor nerve fiber

Question 2

what are the smaller motor units used for?

Answer 2

fine motor control

Question 3

what is a neuromuscular junction?

Answer 3

a site where a nerve fiber communicates w/ a muscle fiber

Question 4

a neuromuscular junction is a type of ___

Answer 4

synapse

Question 5

the synaptic knob does not touch the muscle fiber but is separated by which structure?

Answer 5

synaptic cleft

Question 6

all of the muscle fibers innervated by a single nerve fiber constitute a ___ unit

Answer 6

motor

Question 7

what is acetylcholine?

Answer 7

the neurotransmitter released at a neuromuscular junction

(from nerve cell to muscle cell)

Question 8

actions that require physical strength typically involve which of the following?

Answer 8

large motor units

Question 9

what is a difference in electrical charge from one point to another called?

Answer 9

electrical potential

Question 10

a synapse is the point where a nerve fiber meets a target cell. When the target cell is a muscle fiber, this type of synapse is called a ___ junction

Answer 10

neuromuscular

Question 11

what is the indented region of the sarcolemma that participates in the neuromuscular junction called?

Answer 11

motor end plate

Question 12

w/in a synapse, a neuron ends in a swelling called a(n) ___ terminal

Answer 12

axon

Question 13

in an NMJ, after acetylcholine diffuses across the synaptic cleft, where does it bind to ligand-gated channels?

Answer 13

on the sarcolemma

Question 14

the neurotransmitter used in a neuromuscular junction is ___

Answer 14

acetylcholine

Question 15

the voltage measured across the muscle cell at rest is about -90mV and is called the resting membrane ___

Answer 15

potential

Question 16

a neuromuscular junction is a type of ___

Answer 16

synapse