Physiological contracture
A. occurs when muscles are resting.
B. is a condition in which cross-bridges cannot release.
C. is caused by an abundance of ATP in muscle fibers.
D. results when muscles are well exercised.
E. results when the neurotransmitter remains in the receptor.
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Question 2) Rigor mortis occurs after death because
A. cross-bridges form but can't release.
B. calcium is actively transported back to the sarcoplasmic reticulum.
C. anaerobic respiration is occurring.
D. myosin levels decline at death.
E. cross-bridges never form.
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Question 3) During resting conditions, _________ is synthesized to store energy?
A. calcium
B. creatine phosphate
C. creatine
D. lactic acid
E. pyruvic acid
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Question 4) You are hired to work in a laboratory to measure the rate of human muscle contraction. Which of the following might decrease in quantity in muscle cells undergoing contractions?
A. ATP
B. carbon dioxide
C. water
D. lactic acid
E. sodium
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Question 5) Which of the following would contribute to muscular fatigue in the muscle fiber?
A. the emotional state of an individual
B. depletion of ATP reserves
C. inability of the motor neuron to produce sufficient quantities of acetylcholine
D. depletion of neurotransmitter
E. blocked receptors in the postsynaptic membrane
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Question 6) The type of muscle fatigue known as psychological fatigue is the result of
A. depleted ATP reserves.
B. increased calcium ion concentration in the sarcoplasm.
C. decreased levels of acetylcholine.
D. the emotional state of an individual.
E. None of these choices is correct.
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Question 7) An isometric contraction is described as
A. action potential frequency is high enough that no relaxation of muscle fibers occurs.
B. a muscle produces constant tension during contraction.
C. a muscle produces an increasing tension as the length remains constant.
D. a muscle produces increasing tension as it shortens.
E. a muscle produces tension, but the length of the muscle is increasing.
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Question 8) A concentric contraction is described as
A. action potential frequency is high enough that no relaxation of muscle fibers occurs.
B. a muscle produces constant tension during contraction.
C. a muscle produces an increasing tension during contraction.
D. a muscle produces increasing tension as it shortens.
E. a muscle produces tension, but the length of the muscle is increasing.
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Question 9) Concentric contractions occur when
A. the muscle produces increasing tension as it shortens.
B. the tension and length of the muscle remain constant during a contraction.
C. tension in a muscle is maintained while the muscle increases in length.
D. the muscle produces tension while the length of the muscle increases.
E. isometric contractions occur.
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Question 10) An isotonic contraction is described as
A. action potential frequency is high enough that no relaxation of muscle fibers occurs.
B. a muscle produces constant tension during contraction.
C. a muscle produces an increasing tension during contraction.
D. a muscle produces increasing tension as it shortens.
E. a muscle produces tension, but the length of the muscle is increasing.