During 1. contraction, muscles shorten _________________ , and
lengthen_________________ . (p. 276)
forcefully, forcefully
forcefully, passively
passively, forcefully
passively, passively
2. Muscle cells that are cylindrical and branched, each with a single, centrally located
nucleus, and that contract spontaneously are (p. 277)
cardiac muscle.
skeletal muscle.
smooth muscle.
unknown: not enough characteristics to determine the type of muscle
3. _________________ surrounds each muscle fasciculus, whereas
_________________ surrounds each muscle fiber. (p. 277)
epimysium, perimysium
perimysium, endomysium
epimysium, endomysium
endomysium, perimysium
endomysium, epimysium
4. Which of these layers of a skeletal muscle is the same as the fascia? (p. 277)
sarcolemma
perimysium
fasciculus (bundle)
epimysium
endomysium
5. Each muscle cell is a (p. 278)
fasciculus.
sarcomere.
fiber.
myofibril.
myofilament.
6. Most of the interior of muscle fibers is filled with (p. 278)
fasciculi.
myofibrils.
nuclei.
sarcoplasm.
sarcoplasmic reticulum.
7. Which of these units contains overlapping actin and myosin myofilaments? (p. 278)
A band
H zone
I band
M line
Z disk
8. Which of these units contains the Z disk? (p. 278)
A band
H zone
I band
M line
9. Which of these is NOT a part of the actin myofilament? (p. 278)
actin
cisternae
tropomyosin
troponin
10. Which of these locations has the ability to break down ATP, which releases energy?
(p. 278)
globular actin molecule
head of myosin molecule
troponin molecule
tropomyosin molecule
troponin-tropomyosin complex
11. Troponin binds to (p. 278)
actin.
calcium ions.
tropomyosin.
all of these
12. The enlarged areas of the sarcoplasmic reticulum near the T tubules are the (p. 280)
sarcolemma.
sarcomeres.
terminal cisternae.
troponin molecules.
tropomyosin molecules.
13. In the neuromuscular junction, the axon is also called the (p. 283)
postsynaptic membrane.
presynaptic terminal.
synaptic cleft.
synaptic vesicle.
14. Which of these regions shorten(s) during skeletal muscle contraction? (p. 276-286)
A band
I band
H zone
both a and b
both b and c
15. Given these events: 1. Acetylcholine is released from synaptic vesicles 2. An action
potential reaches the presynaptic terminal 3. Ca 2+ ions diffuse into the cell 4.
Acetylcholine is secreted from the presynaptic terminal by exocytosis - Choose the
arrangement that lists the events in the order they occur when an action potential
travels through the axon of a motor neuron. (p. 283)
1,2,3,4
1,3,4,2
2,1,3,4
2,3,1,4
3,2,1,4
16. Given these events: 1. Acetylcholine binds to receptors on the postsynaptic
membrane 2. Acetylcholinesterase breaks down acetylcholine 3. Choline is reabsorbed
by presynaptic membrane 4. Depolarization of postsynaptic membrane occurs 5.
Ligand-gated Na+ ion channels open - Choose the arrangement that lists the events in
the order they occur when an action potential travels through the axon of a motor
neuron. (p. 283)
1,2,3,4,5
1,5,4,2,3
2,1,3,4,5
4,3,2,1,5
5,4,1,2,3
17. If a person lacks acetylcholinesterase, which of these conditions occurs? (p. 283)
One presynaptic action potential yields one postsynaptic action potential.
One presynaptic action potential yields many postsynaptic action potentials.
Many presynaptic action potentials yield one postsynaptic action potential.
Many presynaptic action potentials yield no postsynaptic action potential.
No action potentials occur in either presynaptic or postsynaptic membranes.
18. The drug atropine blocks neurotransmitter receptors on the postsynaptic terminal of
the neuromuscular junction. This causes (p. 283-284)
flaccid paralysis.
spastic paralysis.
no change in muscle function.
19. Given these events: 1. Action potential travels along the sarcolemma 2. T tubules
undergo depolarization 3. Voltage-gated Ca 2+ ion channels in sarcoplasmic reticulum
open 4. Ca2+ ions diffuse into the sarcoplasm 5. Ca 2+ ions bind to troponin molecules Choose the arrangement that lists these events in the order they occur following a
single stimulation of a skeletal muscle cell. (p. 283-284)
1,2,3,4,5
1,3,5,4,2
2,1,3,4,5
3,1,5,2,4
4,5,12,3
20. During muscle contraction, which of these processes requires ATP? (p. 286-288)
transport of calcium ions into the sarcoplasmic reticulum
release of cross-bridges
formation of cross-bridges
active transport of Na+ and K+ ions
all of these
21. Cross bridges form during muscle contraction when myosin comes in contact with
active sites on (p. 286)
troponin molecules.
tropomyosin molecules.
calcium ions.
acetylcholine molecules.
actin molecules.
22. Given these events: 1. Active sites actin on myofilament are exposed 2. Actin
myofilament slides over myosin myofilament 3. Ca2+ ion binds to troponin 4. Myosin
heads move 5. Cross bridges form - Choose the arrangement that lists the correct order
in which they occur during a single stimulation of a skeletal muscle. (p. 286)
4,3,2,1,5
3,1,5,4,2
3,2,5,4,1
2,4,3,5,1
1,2,3,4,5
23. For cross bridge release, it is necessary for \ul\ulnone to attach to the myosin head.
(p. 286)
a tropomyosin molecule
ATP
Ca2+ ions
a troponin molecule
the sarcolemma
24. Which of these is (are) required for the relaxation of a muscle fiber? (p. 286-288)
ATP
Ca2+ ion uptake into the sarcoplasmic reticulum
acetylcholinesterase activity
no additional stimulation of the neuron
all of these
25. A motor unit is (p. 288)
all the fibers in one muscle.
all the fibers in one fasciculus.
all the muscle fibers innervated by a single motor neuron.
all the nerves that innervate one muscle fiber.
26. Even though each muscle fiber responds in all-or-none fashion, a whole muscle can
contract with varying force because of (p. 289)
different threshold values of each fiber.
total tetanus of the muscle.
multiple motor unit summation.
rigor mortis.
the lag phase of contraction.
27. Multiple-wave summation is caused by (p. 290)
stimuli of increasing size.
increasing number of nerves stimulated.
increasing frequency of stimuli.
complete relaxation between stimuli.
a subthreshold stimulus.
28. Which of these processes results in an increase in the force of contraction of a
whole muscle? (p. 289-291)
multiple motor unit summation
multiple wave summation
treppe
all of these
29. Unlike neurons, muscle fibers have no (p. 289-291)
absolute refractory period.
action potentials.
resting membrane potential.
cell membrane.
mitochondria.
30. A muscle contraction in which the muscle produces an increasing tension, but the
length remains constant is a(n) (p. 292-293)
isometric contraction.
isotonic contraction.
concentric contraction.
eccentric contraction.
31. The most common type of fatigue is: (p. 293-294)
muscular fatigue
psychologic fatigue
synaptic fatigue
sarcoplasmic reticulum fatigue
army fatigue
32. Which of these is responsible for rigor mortis? (p. 295)
tropomyosin covers the active sites on the actin.
Ca2+ ions leak out of the sarcoplasmic reticulum.
actin and myosin cannot come into contact.
tropomyosin molecules use up the remaining ATP molecules.
too many Ca2+ ions are moved back into the sarcoplasmic reticulum.
33. Anaerobic respiration (p. 295)
produces 38 ATP\rquote s per glucose molecule.
produces an oxygen debt.
occurs in resting muscles or muscles undergoing long-term exercise.
can use fatty acid to produce ATP.
all of these
34. Given these sources of energy during exercise: 1. Anaerobic respiration 2. Aerobic
respiration 3. ATP and creatine phosphate in the cell - The correct sequence for the use
of these energy sources by muscle cells when an individual starts exercising is (p. 295296)
1,2,3
1,3,2
2,1,3
3,2,1
3,1,2
35. Fast-twitch muscle fibers (p. 296-297)
are more resistant to fatigue than slow-twitch fibers.
have a richer blood supply than slow-twitch fibers.
have a larger amount of stored glycogen than slow-twitch fibers.
have more mitochondria than slow-twitch fibers.
have more myoglobin than slow-twitch fibers.
36. Fatty acids can be used as an energy source for muscle contraction during (p. 296)
aerobic exercise.
fast, intense exercise.
anaerobic respiration.
breakdown of glycogen to glucose.
the time of oxygen debt.
37. Which of these is correctly matched? (p. 299)
multiunit smooth muscle -- spontaneous contractions
visceral smooth muscle -- contracts when stretched
skeletal muscle -- slower, longer lasting contractions than smooth muscle
multiunit smooth muscle -- numerous gap junctions; autorhythmic
all of these
38. Which of these characteristics is typical of a slow-twitch muscle fiber? (p. 296)
large number of mitochondria
few capillaries
low myoglobin content
largely anaerobic
b, c, and d
39. Which of these is part of the contraction process of smooth muscle? (p. 299)
Calcium ions bind to troponin.
Caveolae bind with calcium to produce cross bridges.
Troponin and tropomyosin are moved.
Calcium ions bind to calmodulin which activates an enzyme.
40. Visceral smooth muscle (p. 299)
responds in an all-or-none fashion to action potentials.
has slow waves of depolarization and repolarization.
has depolarization occur when the cell becomes more permeable to Na + ions and
K+ ions.
requires a stimulus from a neuron or hormone.
produces strong contractions that only last for a few milliseconds.