Tell where each of the three types of muscle tissue would be found in the body. What is meant by the statement, 'Smooth muscles are involuntary in action'?

A muscle fiber relaxes when:

a. the concentration of Ca2+ in the cytosol returns to resting levels.

b. the supply of ATP is exhausted.

c. Ca2+ flood the cytosol.

d. acetylcholine is released from the axon terminal and the sarcolemma depolarizes.

Which of the following energy sources would provide the majority of the ATP for a person running a 26-mile marathon?

a. Stored ATP

b. Glycolytic catabolism

c. Oxidative catabolism

d. Creatine phosphate

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

b. Stimulation by a motor neuron before a muscle fiber has fully relaxed results in a condition called wave summation.

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

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