In smooth muscle, most of the calcium needed for muscle contraction
A. is in the dense bodies.
B. enters from extracellular fluid.
C. is attached to the intermediate filaments.
D. must be activated by myosin kinase.
E. is stored in the sarcoplasmic reticulum.
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Question 2) When comparing smooth and skeletal muscle cells, which of the following statements is true?
A. Smooth muscle cells have striations.
B. The myofilaments in smooth muscle do not form sarcomeres.
C. Smooth muscle cells are larger than skeletal muscle cells.
D. Smooth muscle has a lot of actin and myosin.
E. Smooth muscle cells are multinucleated.
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Question 3) Maureen is hiking in the cold, and to maintain homeostasis her body begins to
A.
increase heat loss from the skin.
B.
release chemicals to initiate a high fever.
C.
shiver.
D.
reduce her blood pressure.
E.
vasodilate vessels in her head and neck.
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Question 4) Susan slipped on the ice and was unable to be fully mobile for several days. What disruption to homeostasis would you predict she experienced during her immobile period in terms of her muscular system?
A.
Susan's metabolic rate was raised and it initiated sweating.
B.
Susan was more cold than usual because her inactivity prevented her muscles from helping to regulate her body temperature.
C.
Susan's uninjured muscles overcompensate for the inactive ones by contracting spontaneously.
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Question 5) Increased strength of a trained muscle is due to
A. an increased number of muscle fibers.
B. the nervous system's ability to recruit a large number of motor units simultaneously.
C. elimination of unnecessary enzymes and metabolic pathways.
D. elimination of all fat deposits.
E. elimination of unnecessary connective tissue.
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Question 6) Betsy took a fall, broke her arm, and when she took the cast off she was alarmed to see that her muscles
A.
looked the same as they did before the fall.
B.
had undergone atrophy.
C.
undergone hypertrophy.
D.
seemed to have an increase in blood flow.
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Question 7) Select the term that does not belong with the others.
A. muscle atrophy
B. immobilization
C. decrease in number of myofibrils
D. loss of nerve stimulation
E. increased vascularity
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Question 8) Aerobic exercise
A. increases vascularity of muscle.
B. develops fatigue-resistant fast-twitch fibers.
C. can increase the efficiency of slow-twitch fibers.
D. can increase the number of mitochondria in muscle cells.
E. All of these choices are correct.
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Question 9) Muscle hypertrophy results from increased numbers of
A. myofibrils and sarcomeres.
B. muscle fibers.
C. motor units.
D. muscles.
E. muscle cells.
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Question 10) Intense exercise that results in a great deal of anaerobic activity
A. converts some slow-twitch fibers into fast-twitch fibers.
B. increases muscular strength and mass.
C. enlarges slow-twitch fibers.
D. decreases the efficiency of fast-twitch fibers.
E. decreases muscle strength and mass.
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