9. Muscle Tissue

True or False: if false, choose the answer that best corrects the statement.

The events of excitation-contraction coupling involve converting the electrochemical signal to the mechanical movement of contraction.

When Eric returned from jogging, he was breathing heavily and sweating profusely, and he complained that his legs ached and felt weak. On the basis of what you have learned about muscle energy metabolism, respond to the following questions:

b. What ATP-harvesting pathway have his working muscles been using that leads to such a breathing pattern?

Voltage gated channels respond to the depolarization of an action potential by releasing Ca$^2$$^+$. Where are these channels located?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

A muscle fiber changes length during isotonic concentric and isotonic eccentric contractions.

The sites where the motor nerve impulse is transmitted from the nerve endings to the skeletal muscle cell membranes are the

a. neuromuscular junctions

b. sarcomeres

c. myofilaments

d. Z discs

Which of the following statements accurately describes the role of ATP in a muscle contraction?

a. ATP is directly responsible for the power stroke.

b. ATP moves troponin and tropomyosin away from actin.

c. ATP breaks the actin/myosin attachment and 'cocks' the myosin head.

d. ATP causes the myofilaments to shorten.