The branch of the nervous system that helps govern smooth muscle contraction is the _______ nervous system.
A. autonomic
B. somatic
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Question 2) To initiate a smooth muscle cell contraction, calcium enters the cell and binds to
A. troponin, which then activates myosin light-chain kinase.
B. calmodulin, which then binds to and activates myosin light-chain kinase.
C. a myosin head, which then activates calmodulin.
D. myosin light-chain kinase, which then hydrolyzes ATP.
E. a phosphatase, which then removes the tropomyosin blockade.
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Question 3) Myosin light-chain phosphatase is an enzyme that dephosphorylates the myosin heads in smooth muscle, which stops ATPase activity and fosters relaxation of smooth muscle.
Indicate whether this statement is true or false.
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Question 4) Energy requirements for smooth muscle contractions are generally higher than those for skeletal muscle contractions.
Indicate whether this statement is true or false.
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Question 5) Within smooth muscle cells, intermediate filaments are linked by dense _________ at points where they attach on the inner surface of the cell membrane.
Fill in the blank with correct word.
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Question 6) The latchbridge mechanism of myosin heads is a property of ________ muscle.
A. cardiac
B. skeletal
C. smooth
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Question 7) Smooth muscle cells tend to be shorter but thicker than skeletal muscle cells.
Indicate whether this statement is true or false.
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Question 8) A term that describes the change in muscle following a lack of exercise is
A. proliferation.
B. hypertrophy.
C. convergence.
D. atrophy.
E. myofascia.
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Question 9) The type of muscle fibers that have only a single nucleus, both thick and thin filaments, but no Z discs, are
A. skeletal.
B. cardiac.
C. smooth.
D. cardiac and smooth.
E. cardiac and skeletal.
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Question 10) Lifting weights will cause muscles to enlarge. This is primarily due to
A. an increase in the number of muscle cells.
B. an increase in the size of muscle cells.
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