Identify the letter that best completes the statement, and answer the questions on the Answer Sheet provided.
1. Thick filaments in skeletal muscle are composed of
a. actin. b. troponin and tropomyosin. c. myosin. d. actin, troponin, and tropomyosin.
2. Sarcomeres are arranged end to end as
a. fascicles. b. myofibrils. c. bands. d. perimysia.
3. Which of the following statements concerning the length-tension relationship of skeletal muscle is incorrect?
a. When a muscle is maximally stretched, it can develop the most tension upon contraction because the thin filaments can slide a maximal distance. b. Maximum tension can be developed if the muscle is at its lowest at the onset of contraction. c. In the body, the relaxed length of muscle is its optimal length. d. When the initial length of muscle prior to contraction becomes very short, tension is decreased during contraction because of thin filament overlap, because the thick filaments are compressed against the Z lines and because less Ca2+ is released during excitation-contraction coupling.
4. Muscle tension
a. is created during muscle contraction as the tension generated by the contractile elements is transmitted via the connective tissue and tendons to the bones. b. is the force exerted on a muscle by the weight of an object. c. is greater than the load during an isometric contraction. d. both b and c