The ions that enter the skeletal muscle cell during the generation of an action potential are
a. Calcium ions
b. Chloride ions
c. Sodium ions
d. Potassium ions

Contraction elicited by a single brief stimulus is called:

a. A twitch

b. Temporal summation

c. Multiple motor unit summation

d. Fused tetanus

A smooth, sustained contraction resulting from very rapid stimulation of the muscle, in which no evidence of relaxation is seen, is called:

a. A twitch

b. Temporal summation

c. Multiple motor unit summation

d. Fused tetanus

During muscle contraction, ATP is provided by:

a. a coupled reaction of creatine phosphate with ADP

b. aerobic respiration of glucose, and

c. anaerobic glycolysis.

______ (1) Which provides ATP fastest?

______  (2) Which does (do) not require that oxygen be available?

______  (3) Which provides the highest yield of ATP per glucose molecule?

______  (4) Which results in the formation of lactic acid?

______  (5) Which has carbon dioxide and water products?

______  (6) Which is most important in endurance sports?

The neurotransmitter released by somatic motor neurons is:

a. Acetylcholine

b. Acetylcholinesterase

c. Norepinephrine

Myoglobin has a special function in muscle tissue. It:

a. Breaks down glycogen

b. Is a contractile protein

c. Holds a reserve supply of oxygen in the muscle

Aerobic exercise results in all of the following except:

a. More capillaries surrounding muscle fibers

b. More mitochondria in muscle cells

c. Increased size and strength of existing muscle cells

d. More myoglobin

What is the importance of acetylcholinesterase in muscle cell contraction?

Explain what is meant by the term excitation-contraction coupling.