Muscles 1

Front 1

A motor neuron and all of the skeletal muscle cells it stimulates is called a

Back 1

motor unit

Front 2

The axon of each motor neuron has numerous endings called

Back 2

axon terminal

Front 3

The actual gap between an axonal ending and the muscle cell is called a

Back 3

synaptic cleft

Front 4

Within the axonal endings are many small vesicles containing a neurotransmitter called

Back 4

acetylcholine (ACh)

Front 5

When the ________ reaches the ends of the axon, the neurotransmitter is released, and it diffuses to the muscle cell membrane to combine with receptors there.

Back 5

nerve impulse or action potential

Front 6

Binding of the neurotransmitters with muscle membrane receptors causes the membrane to become permeable to sodium, resulting in the influx of sodium ions and ________ of the membrane.

Back 6

depolarization

Front 7

Acetylcholine is released into the neuromuscular junction by the axon terminal

Back 7

1

Front 8

The action potential, carried deep into the cell, causes the sarcoplasmic reticulum to release calcium ions

Back 8

4

Front 9

The muscle cell relaxes and lengthens

Back 9

7

Front 10

Acetylcholine diffuses across the neuromuscular junction and binds to receptors on the sarcolemma

Back 10

2

Front 11

The calcium ion concentration at the myofilaments increases; the myofilaments slide past one another, and the cell shortens

Back 11

5

Front 12

Depolarization occurs, and the action potential is generated

Back 12

3

Front 13

As calcium is actively reabsorbed into the sarcoplasmic reticulum, its concentration at the myofilaments decreases

Back 13

6