Myoglobin has a special function in muscle tissue. Ita. breaks down glycogen,b. is a contractile protein,c. holds a reserve supply of oxygen in the muscle.

A smooth, sustained contraction resulting from very rapid stimulation of the muscle, in which no evidence of relaxation is seen, is calleda. a twitch,b. temporal summation,c. multiple motor unit summation,d. fused tetanus.

During muscle contraction, ATP is provided bya. a coupled reaction of creatine phosphate with ADP,b. aerobic respiration of glucose, andc. 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 isa. acetylcholine,b. acetylcholinesterase,c. norepinephrine.

The ions that enter the skeletal muscle cell during the generation of an action potential area. calcium ions,b. chloride ions,c. sodium ions,d. potassium ions.

Aerobic exercise results in all of the following excepta. 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.

Define and draw a motor unit.