Physiology of Muscle Contraction

Where is calcium stored in the muscle cell?

• T Tubules

• Sarcoplasmic Reticulum (SR)

• Sarcolemma

• Sarcomere

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

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

• troponin

• tropomyosin

• actin

• 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

What must occur first before a muscle can contract?

• An action potential must develop as energy/nutrients is gained from the digestive system

• An action potential must travel to the muscle through the circulatory system

• An action potential must enter the body through the respiratory system

• An action potential must be sent through neurons in the nervous system

One brief contraction in response to a single threshold stimulus is _____.

• a twitch

• incomplete tetany

• contracture

• tetanus

What is the name of the place where a nerve meets a muscle fiber

• Nerve junction

• Neuromuscular junction

• Muscle junction

• Crossbridge

____________ attaches to actin to form the cross bridge.

• Troponin

• Tropomyosin

• Myosin

• Calcium

What causes the sodium channels on the muscle membrane (sarcolemma) to open?

• Acetylcholine binds to the Na+ channel

• Acetylcholine binds to the synaptic vesicles

• the Ca2+ channels open

• The action potential is generated in the muscle cell

Match the following:

• Thin fibers

• Myosin

• Muscle fibers

• Myofibrils

• Thick fibers

• Actin