The increase in muscle tension that occurs with an increase in the intensity (voltage) of a stimulus is called
A. recruitment.
B. treppe.
C. wave summation.
D. incomplete tetany.
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Question 2) The contraction phase of a muscle twitch has a shorter duration than the relaxation phase.
Indicate whether this statement is true or false.
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Question 3) A subthreshold stimulus evokes only a small muscle twitch instead of a full tetanic contraction.
Indicate whether this statement is true or false.
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Question 4) The most prevalent of skeletal muscle fibers in the body are _____ fibers.
A. slow-twitch
B. fast-twitch
C. intermediate
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Question 5) Events of excitation contraction coupling, such as the release of calcium from intracellular stores, occur during the ________ period of a muscle twitch.
A. relaxation
B. contraction
C. latent
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Question 6) One of the reasons you might struggle to lift a heavy object with your arm fully extended is because
A. in extension, the proximity of Z discs to thick filaments restricts the sliding movement within sarcomeres.
B. full extension results in decreased overlap between thick and thin filaments in the muscle.
C. in that posture, some myosin heads overlap actin in the wrong orientation and tug actin in the wrong direction.
D. motor neurons cannot release as much ACh in that posture.
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Question 7) One's genes have a greater impact than exercise habits in determining the proportion of fast-twitch and slow-twitch fibers throughout the body.
Indicate whether this statement is true or false.
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Question 8) Muscles of the eye and hand have a high percentage of _______ fibers.
A. fast-twitch
B. slow-twitch
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Question 9) Release of crossbridges and a decline in muscle tension characterize the _______ period of a twitch.
A. contraction
B. latent
C. relaxation
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Question 10) Which fibers dominate many of the back and calf muscles that contract almost continually to maintain posture?
A. Slow-twitch
B. Fast-twitch
C. Intermediate
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