Each _____ includes a Z disk and extends from each side of the Z disk to the ends of the myosin myofilaments.
A.
isotropic band or I band
B.
anisotropic band or A band
C.
muscle fiber
D.
sarcomere
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Question 2) If all of the calcium within a muscle fiber was removed, which of the following could still occur?
The heads of the myosin myofilaments bind to G-actin to form cross-bridges.
An action potential that was produced at the neuromuscular junction is propagated along the sarcolemma.
The troponin molecules bound to G actin molecules are released, causing tropomyosin to move.
The heads of the myosin molecules return to their resting position and the recovery stroke occurs.
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Question 3) In order for the excitation-contraction coupling to occur, the production of an action potential must occur within the ______ of a muscle fiber.
A.
contraction
B.
sarcolemma
C.
junction
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Question 4) As muscle activity increases, the body temperature _____.
A.
decreases
B.
increase
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Question 5) Why does muscle activity affect the temperature of the body?
A.
The rate of chemical reactions increases in muscle fibers during contraction, so the rate of heat production also increases.
B.
Muscle contraction generates pyrogens which reset the body's internal thermostat to a higher temperature.
C.
Muscle activity directs more warm blood to the muscles away from the central core causing a cooling effect on your internal organs.
D.
Increased muscle activity causes a rise in adipose stores which increases the insulation value of the body.
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Question 6) In a contracted muscle, the A bands do narrow because the length of the myosin myofilaments changes,.
Indicate whether the statement is true or false.
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Question 7) Shivering raises body temperature because:
it decreases warm blood flow to the core while increasing flow to the muscles
it depresses metabolism
it increases heat production up to 18 times that of resting levels
the process of muscle contraction produces heat
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Question 8) Atrophy at the neuromuscular junction that naturally occurs with age would have what effect on muscles?
A.
It would stimulate the nervous system to increase the speed in which it sends action potentials to the myofiber.
B.
It would stimulate muscle cramps.
C.
It would decrease the number of action potentials sent to the myofiber.
D.
It would cause an increase in the amount of ACh released by the neurons to compensate.
E.
It would have no effect on the muscles.
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Question 9) During a muscle fiber contraction, which of the following decreases in size?
A band
entire sarcomere
H zone
I band
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Question 10) The figure illustrates a detailed drawing of the neuromuscular junction. What does E represent?
A. synaptic vesicles
B. synaptic cleft
C. sarcolemma
D. presynaptic terminal
E.
postsynaptic membrane
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