Some skeletal muscle fibers are “fast-twitch” fibers (white fibers), and others are “slow-twitch” (red) fibers. Would you expect an athlete proficient in running the 100-yard dash to have a greater proportion of red fibers or white fibers in muscles of the leg? Why?

Muscle Physiology

1. Some skeletal muscle fibers are “fast-twitch” fibers (white fibers), and others are “slow-twitch” (red) fibers. Would you expect an athlete proficient in running the 100-yard dash to have a greater proportion of red fibers or white fibers in muscles of the leg? Why? 
2. Define the following:
1. Maximal stimulus
2. Threshold stimulus
3. Submaximal stimulus
3. A skeletal muscle can be stimulated, under laboratory conditions, with a supramaximal stimulus. Is it possible for the muscle to respond with a supramaximal contraction? Explain
4. Define a motor unit. Of what physiological advantage is a small motor unit arrangement in skeletal muscle?
5. Explain why a latent period is observed between the application of a stimulus and contraction of the stimulated muscle.
6. Explain, giving two causative factors, why skeletal muscle displays fatigue.
7. Does complete or incomplete tetanus occur physiologically? Explain.
8. Define the following:
1. Isometric contraction
2. Isotonic contraction
3. Optimum length (load)
9. Define the following:
1. Electromyography
2. Dynamometry
10. What does the term motor unit recruitment mean?
11. Are you right-handed, left-handed, or ambidextrous? Which hand took the longest time to fatigue? Explain.
12. Define the following:
1. Muscle tonus
2. Spastic paralysis
3. Flaccid paralysis
13. Poliomyelitis affects the anterior horn of the spinal gray matter. Would you expect the polio patient to exhibit spastic or flaccid paralysis? Why?
14. Is the brain necessary for spinal reflex activity to occur? Why or why not?
15. List in correct sequence the major components of a spinal reflex arc.