Physiology of Muscle Contraction

Where a nerve and muscle fiber come together is called a...

• Synaptic Cleft

• Neurotransmitter

• Neuromuscular Junction

• Action Potential

The neurotransmitter stored in the axon terminal identified as ...

• Acetylcholine

• Serotonin

• Adrenaline

• Dopamine

Where is calcium stored in the muscle cell?

• T Tubules

• Sarcoplasmic Reticulum (SR)

• Sarcolemma

• Sarcomere

When the action reaches the muscle cell, it travels down the....

• Sarcolemma

• T Tubules

• Sarcoplasmic Reticulum

• Calcium Channel

The action potential releases __________ from the Sarcoplasmic Reticulum (SR)

After calcium is released from the SR, it binds to _________

• troponin

• tropomyosin

• actin

• myosin

Troponin moves the ____________ uncovering binding sites.

• actin

• troponin

• tropomyosin

• myosin

A calcium deficiency would

• create uncoordinated muscle contractions

• allow muscle contraction, but not relaxation

• prevent contraction by preventing myosin from binding to actin

• have no effect on contraction

_______ binds to myosin head causing myosin to release actin.

• ATP

• ADP

• Actin

• Calcium

What would be the correct order of the steps?

1. Action potential travels down T-tubules.
2. Nerve impulse reaches the muscle.
3. Calcium binds to troponin.
4. Tropomyosin moves.

• 1, 2, 3, 4

• 4, 3, 2, 1

• 3, 4, 1, 2

• 2, 1, 3, 4