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Active Lecture Questions
CHAPTER
9
Muscles and
Muscle Tissue
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Muscle cells are referred to as ________.
a. muscle fibers
b. muscle spindles
c. muscle myosin
d. muscle actin
Copyright © 2010 Pearson Education, Inc.
Which of the following is not a prefix used
to refer to muscle?
a. Mys
b. Myo
c. Sarco
d. Lemma
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Of the following muscle types, which is the
only one subject to conscious control?
a. Smooth
b. Skeletal
c. Cardiac
d. All of these muscle types are subject to
conscious control.
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Which two types of muscle appear striated
when examined under a microscope?
a. Smooth and skeletal
b. Smooth and cardiac
c. Cardiac and skeletal
d. Skeletal muscle is the only striated muscle
type.
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Which of the following muscular functions
serves a metabolic function?
a. Movement
b. Posture maintenance
c. Joint stabilization
d. Heat generation
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In order to receive a signal to contract, each
skeletal muscle must be served by a(n)
________.
a. artery
b. nerve
c. vein
d. ligament
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The elastic components of muscle consist
of which elements?
a. Tendon, epimysium, muscle fiber
b. Bone, perimysium, blood vessel
c. Fascicle, bone, blood vessel
d. Tendon, epimysium, perimysium,
endomysium
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Which of the following components
accounts for the bulk of muscle fiber
volume (up to 80%)?
a. Glycosomes
b. Mitochondria
c. Myofibrils
d. Sarcoplasm
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The functional unit of a muscle fiber is the
__________.
a. sarcomere
b. myofibril
c. fascicle
d. myofilament
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Which portion of a myosin molecule would
be the most severely affected upon
exposure to an enzyme inhibitor?
a. Tail
b. Hinge region
c. Head
d. The actin molecule
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The thin filaments are not comprised of
which of the following components?
a. Actin
b. Titin
c. Troponin
d. Tropomyosin
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What is the major function of the
sarcoplasmic reticulum?
a. Store sodium ions
b. Expel sodium ions from the cell
c. Expel calcium ions from the cell
d. Store calcium ions
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What would happen to intracellular calcium
levels if a muscle fiber were treated with a
calcium channel–blocking drug?
a. Intracellular calcium levels would increase.
b. Intracellular calcium levels would
decrease.
c. Intracellular calcium levels would be
unchanged.
d. The muscle fiber would shrink.
Copyright © 2010 Pearson Education, Inc.
What is the significance of the muscle fiber
triad relationship?
a. The terminal cisternae subdivide the
sarcolemma.
b. The T tubules bring calcium to the
sarcoplasmic reticulum.
c. The sarcoplasmic reticulum transfers
calcium to the T tubules.
d. The T tubules conduct electrical impulses
that stimulate calcium release from the
sarcoplasmic reticulum.
Copyright © 2010 Pearson Education, Inc.
During a muscle contraction, the sliding
filament theory would be apparent in a
sarcomere because __________.
a. the I bands get longer
b. the A bands get shorter
c. the H zone becomes less obvious and the
Z discs move closer together
d. the Z discs get pulled closer to the I bands
and the H zone becomes more obvious
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At the neuromuscular junction, the muscle
contraction initiation event is ______.
a. a release of calcium ions from the
sarcoplasmic reticulum
b. conduction of an electrical impulse down
the T tubules
c. binding of acetylcholine to membrane
receptors on the sarcolemma
d. sliding of actin and myosin filaments past
each other
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What would be the response of a muscle
fiber treated with an acetylcholinesterase
inhibitor?
a. There would be a continued muscle fiber
contraction in the absence of additional
nervous system stimulation.
b. The muscle fiber would be nonresponsive
to acetylcholine.
c. Acetylcholine would be retained in the
axon ending.
d. The muscle fiber would contract then relax
for a prolonged period of time.
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In a muscle fiber, the key intracellular event
that stimulates muscle contraction is known
as ________.
a. polarization
b. depolarization
c. repolarization
d. potential
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During depolarization, the sarcolemma is
most permeable to _______.
a. sodium ions
b. potassium ions
c. calcium ions
d. chloride ions
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The time period between action potential
initiation and mechanical activity of a
muscle fiber is called the _________.
a. latent period
b. refractory period
c. action potential
d. excitation period
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What is calcium’s function during muscle
contraction?
a. Calcium binds to troponin, changing its
shape and removing the blocking action of
tropomyosin.
b. Calcium binds to troponin to prevent
myosin from attaching to actin.
c. Calcium depolarizes the muscle fiber.
d. Calcium flows down the T tubules to
stimulate the influx of sodium from the
sarcoplasmic reticulum.
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Corpses usually exhibit rigor mortis
because __________.
a. ATP hydrolysis is stimulating myosin head
attachment to actin
b. a lack of ATP hydrolysis prevents myosin
head detachment from actin
c. calcium stores become deficient
d. sodium stores become deficient
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Small precise movements are controlled by
______ motor units.
a. small
b. large
c. many
d. few
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A muscle contraction increases in strength
up to a point because ________.
a. stronger stimuli inhibit motor unit activation
b. recruitment occurs and more motor units
respond to stronger stimuli
c. more calcium is available in the
sarcoplasm
d. additional neurons begin stimulating each
muscle fiber
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Isometric contractions come into play when
an individual is ________.
a. jumping
b. walking uphill
c. lifting a heavy object
d. maintaining an upright posture
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A sprinter is more likely to depend on
_______ respiration to generate ATP,
whereas a Tour de France cyclist is more
likely to rely on __________ respiration.
a. anaerobic; aerobic
b. aerobic; anaerobic
c. aerobic; aerobic
d. anaerobic; anaerobic
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Sprinters typically possess more ________
muscle fibers.
a. slow glycolytic
b. fast glycolytic
c. slow oxidative
d. fast oxidative
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A major difference between smooth muscle
fibers and skeletal muscle fibers in terms of
calcium influx is that ______.
a. smooth muscle fibers have a sarcoplasmic
reticulum
b. calcium ions are stored in the sarcoplasm
of smooth muscle
c. calcium ion influx occurs mostly from the
extracellular fluid in smooth muscle
d. smooth muscle contraction does not
involve calcium
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A major cellular feature in smooth muscle
that contributes to its rhythmicity and
ability to participate in peristalsis is the
presence of _________.
a. troponin complex
b. gap junctions
c. varicosities
d. caveolae
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The principal neurotransmitter of skeletal
muscle is acetylcholine. The major
neurotransmitter(s) of smooth muscle is
(are) _______.
a. acetylcholine
b. epinephrine
c. norepinephrine
d. all of the above
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