Quiz 4

Question 1

What promotes release of ACh from the presynaptic neuron?

Answer 1

Action Potential

Question 2

Sodium channels in the sarcolemma

Answer 2

voltage-gated ions

Question 3

-55mV

Answer 3

threshold potential

Question 4

Basic contractile unit of a muscle fiber?

Answer 4

Sarcomere

Question 5

T-tubules are an infolding of this structure

Answer 5

Sarcolemma

Question 6

Removes neurotransmitter from the NMJ

Answer 6

Acetylcholinesterase

Question 7

The space between a motor neuron and a muscle

Answer 7

synaptic cleft

Question 8

Neurotransmitter at the neuromuscular junction

Answer 8

Acetylcholine

Question 9

What forms a triad?

Answer 9

Two terminal cisternae and a T-tubule.

Question 10

Storehouse for calcium within a muscle fiber?

Answer 10

Terminal cisternae

Question 11

Connection of a myosin head with the active site on an actin?

Answer 11

Cross bridge

Question 12

A membrane potential more than -70mV

Answer 12

Hyperpolarization

Question 13

Connective tissue covering around an entire muscle?

Answer 13

Epimysium

Question 14

What is the cell membrane of a muscle cell called?

Answer 14

Sarcolemma

Question 15

What is the major protein that comprises a thin filament?

Answer 15

Actin

Question 16

What molecule covers the active sites of the thing filaments when the muscle is at rest?

Answer 16

Tropomyosin

Question 17

What molecule is found in the thick filaments and is shaped like a golf club?

Answer 17

Myosin

Question 18

Which component of a thin filament binds with calcium and regulates the formation of cross bridges?

Answer 18

Troponin

Question 19

What region of a neuron is known as the “Trigger zone”?

Answer 19

Axon Hillock

Question 20

What type of membrane protein gives the “Trigger zone” its ability to initiate an action potential?

Answer 20

Voltage-gated ion channels.

Question 21

Which voltage-gated ion channel opens first during the propagation of an action potential?

Answer 21

Na+

Question 22

Which component of a voltage-gated Na+ channel is open when the cell is at rest?

Answer 22

Inactivation gate

Question 23

When does stimulation of cell #2 cease?

Answer 23

When neurotransmitter can diffuse from the cleft, neurotransmitter can be broken down by an enzyme, and/or neurotransmitter can be reabsorbed by the neuron for future use.