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

Muscle tone is:

a. The result of voluntary shortening of the muscle.

b. The result of a small amount of involuntary activation of motor units by the nervous system.

c. Abnormal—a person's muscles should be relaxed normally.

d. Present only where there is damage to the nervous system.

Resistance-type activities will likely rely on _______ energy sources, whereas endurance activities will probably rely on _____ energy sources.

Which of the following is not likely to result from endurance training alone?

a. Increase in oxidative enzymes in the muscle fiber

b. Increased numbers of mitochondria

c. Hypertrophy of the muscle fibers

d. Increase in blood supply to the muscle fibers

Which of the following factors is/are responsible for muscular fatigue?

a. Accumulation of chemicals, including calcium and phosphate ions & increased blood flow to the muscle

b. Decreased availability of oxygen

c. Psychological and environmental factors

d. Depletion of key metabolic fuels, such as creatine phosphate

What is thought to cause excess postexercise oxygen consumption?

List some of the functions of smooth muscle tissue.

Which of the following best describes single-unit smooth muscle tissue?

a. The fibers function individually.

b. It is found in organs that require precise control of contraction.

c. It contains gap junctions that couple the fibers electrically.

d. The amount of tension produced varies with the number of muscle cells recruited.

Mark the following statements as true for smooth muscle tissue, cardiac muscle tissue, and/or skeletal muscle tissue.          

a. _________ Actin attaches to dense bodies.          ​​​​

b. _________ Cells are joined by intercalated discs.          ​​​​

c. _________ The thick and thin filaments are arranged into sarcomeres.          ​​​​

d. _________ The thick filaments contain myosin heads along their entire length.          ​​​​

e. _________ The cells depolarize and contract as a unit.          ​​​​

f. _________ Ca²⁺ binding to troponin is the initiating event of contraction.          ​​​​

g. _________ Ca²⁺ binding to calmodulin is the initiating event of contraction.          ​​​​

h. _________ The sarcolemma has a distinct motor end plate.