The function of the T tubules in muscle contraction is toa. make and store glycogen,b. release Ca²⁺ into the cell interior and then pick it up again,c. transmit the action potential deep into the muscle cells,d. form proteins.

The primary action of the biceps brachii muscle of the anterior arm is to flex the forearm at the elbow. However, when this muscle is inflamed, pain is felt in the shoulder. Explain this finding.

Which of the following types of muscle fibers have low myosin ATPase activity and are classified as slow-twitch?

a. Type I fibers

b. Type IIa fibers

c. Type IIx fibers

d. Type III fibers

Mr. Nasheed has cerebral palsy and suffers severe skeletal muscle spasms as a result of his condition. He is prescribed the drug dantrolene, which prevents the release of Ca2+ from the SR. Explain how this will treat his muscle spasms.