Chapter 10 Muscle Tissue
119. The most abundant form of smooth muscle is A. single-unit, which is also known as visceral smooth muscle. B. cardiac muscle, which is also known as visceral smooth muscle. C. multiunit, which is also known as visceral smooth muscle. D. multiunit, which is also known as varicose muscle. E. single-unit, which is also known as somatic nervous system muscle.
A
34. The presence of mitochondria and myoglobin facilitate _________ respiration in muscle cells. A. aerobic B. anaerobic
A
42. Which structures are reservoirs that store acetylcholine? A. Synaptic vesicles B. Synaptic clefts C. Terminal cisternae D. Lysosomes E. Sarcomeres
A
62. The net energy yield from one glucose molecule through the process of glycolysis is A. 2 ATP. B. 6 ATP. C. 30 ATP. D. 36 ATP.
A
71. Oxidative fibers are A. red and fatigue-resistant. B. red and fatigable. C. white and fatigue-resistant. D. white and fatigable.
A
76. 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
A
99. One of the most crucial factors in the development of fatigue appears to be a depletion of ATP.
FALSE
6. The spring-like property that returns muscle to its original length after a contraction ends is A. extensibility. B. elasticity. C. contractility. D. treppe effect. E. conductivity.
b
93. When a muscle is isometrically contracted, its length _______ change. A. does B. does not
B
122. This sarcomere depicts relaxed muscle. Which number identifies the M line? 7-26-2013 A. 1 B. 3 C. 4 D. 5
C
18. The membranous network that wraps around myofibrils and holds relatively high concentrations of calcium is known as the A. sarcolemma. B. T-tubule. C. sarcoplasmic reticulum. D. sarcomere. E. Golgi body.
C
20. Which are the reservoirs that store the calcium required for muscle contraction? A. Synaptic vesicles B. Synaptic clefts C. Terminal cisternae D. Peroxisomes E. Mitochondria
C
33. A typical skeletal muscle cell contains approximately _____ mitochondria. A. 3 B. 30 C. 300 D. 3000
C
1. The characteristic of muscle that allows it to be passively stretched is A. conductivity. B. elasticity. C. excitability. D. extensibility. E. contractility.
D
10. The structure responsible for attaching muscle to bone is a A. sphincter. B. ligament. C. fascia. D. tendon. E. myofibril.
D
105. A term that describes the change in muscle following a lack of exercise is A. proliferation. B. hypertrophy. C. convergence. D. atrophy. E. myofascia.
D
22. Which is not a protein found in thin filaments? A. Actin B. Troponin C. Tropomyosin D. Sarcomyosin E. No exceptions, all are found in thin filament
D
50. The repolarization of the action potential involves the opening of A. chemically gated Na+ channels. B. voltage-gated Na+ channels. C. chemically gated K+ channels. D. voltage-gated K+ channels.
D
9. Which is the correct order of the connective tissue layers of a skeletal muscle, beginning with the most superficial? a: Endomysium b: Epimysium c: Perimysium A. a, b, c B. b, a, c C. c, a, b D. b, c, a E. c, b, a
D
65. For a sprint lasting 60 seconds, ATP is supplied primarily by A. aerobic respiration only. B. phosphate transfer and glycolysis. C. conversion of lactate to pyruvate. D. phosphate transfer only.
B
73. The type of fibers specialized to continue contracting for extended periods of time, as would be required in running a marathon, for example, are _____ fibers. A. fast-twitch B. slow-twitch C. intermediate
B
75. "Intermediate fiber" is another name for A. a fast-twitch, glycolytic fiber. B. a fast-twitch, oxidative fiber. C. a slow-twitch, glycolytic fiber. D. a slow-twitch, oxidative fiber.
B
89. In a lab, wave summation is demonstrated by increasing the _________ of the stimulus. A. intensity B. frequency C. capacitance D. warm up time
B
44. Acetylcholine is released from a neuron A. by a primary active transport pump. B. by rapid diffusion when a voltage-gated ion channel opens for it. C. through exocytosis when a vesicle fuses with the membrane. D. by conduction through a gap junction from nerve to muscle.
C
102. With increased age, skeletal muscles show A. a decrease in the number of myofibrils. B. an increase in muscle fiber diameter. C. no change in oxygen storage capability. D. increased glycogen reserves. E. a tendency to fatigue less rapidly.
A
11. A flat, thin structure made of dense connective tissue that serves to attach a muscle to a bone (or to another muscle) is a(n) A. aponeurosis. B. tendon. C. perimysium. D. myolemma. E. superficial fascia.
A
30. A sarcomere is defined as the distance from one _____ to the next adjacent ____ . (The same answer fills in both spaces.) A. Z disc B. I band C. H zone D. A band E. M line
A
91. Muscle tone is a result of _________ nervous system activity, and it acts to _________ joint position. A. involuntary, stabilize B. involuntary, continuously vary C. voluntary, stabilize D. voluntary, continuously vary
A
92. Which contraction occurs when you try (unsuccessfully) to move a wall? A. Isometric B. Isotonic
A
94. The top long-distance runners probably have _______ proportion of slow muscle fibers in their leg muscles. A. a higher B. a lower C. the same
A
116. When smooth muscle is stretched for a prolonged period of time, it responds by A. contracting. B. relaxing.
B
46. Which is the neurotransmitter that causes the release of calcium ions from reservoirs within the muscle cell and thereby initiates the steps of contraction? A. Acetylcholinesterase B. Acetylcholine C. Serotonin D. Norepinephrine
B
78. One's genes have a greater impact than exercise habits in determining the proportion of fast-twitch and slow-twitch fibers throughout the body
TRUE
79. The contraction phase of a muscle twitch has a shorter duration than the relaxation phase.
TRUE
90. During REM sleep, muscle tone decreases significantly.
TRUE
97. In general, a muscle's resting length is its optimal length for force generation.
TRUE
5. The property of muscle tissue that allows an impulse to travel down the entire length of the cell membrane is A. elasticity. B. conductivity. C. extensibility. D. contractility. E. responsibility.
b
98. A reduced ability to generate tension due to recent exertion of force is known as muscle ________.
fatigue
103. During aging, muscle is often replaced by dense connective tissue, a process called _________.
fibrosis
17. Satellite cells are multinucleate.
FALSE
59. Phosphate transfer is used for A. immediate ATP needs and is dependent on oxygen. B. immediate ATP needs and is not dependent on oxygen. C. long term ATP needs and is dependent on oxygen. D. long term ATP needs and is not dependent on the presence of oxygen.
B
108. Smooth muscle cells tend to be shorter but thicker than skeletal muscle cells.
FALSE
15. Because skeletal muscle cells are so close together, muscle contains very few blood vessels.
FALSE
64. The electron transport system refers to oxidative phophorylation using the coenzymes FADH2 and _______.
NADH
123. In the hierarchy of skeletal muscle fiber components, the myofibril is made up of myofilaments.
TRUE
67. When someone engages in exercise that requires more oxygen than is available, they develop a(n) _____ _______ (2 words), which results in heavy breathing for several minutes after the exercise is complete.
oxygen debt
88. A continuous, smooth contraction of muscle in which twitches are fully fused is referred to as _________.
tetany
114. The branch of the nervous system that helps govern smooth muscle contraction is the _______ nervous system. A. autonomic B. somatic
A
121. This sarcomere depicts relaxed muscle. What does number 1 refer to? A. A band B. H zone C. Z disc D. M line E. I band
A
14. The multiple nuclei in skeletal muscle cells are the result of the A. fusion of myoblasts. B. cytokinesis of embryonic satellite cells. C. spontaneous development of nuclei in embryonic cells. D. stimulation of fibroblasts by hormones. E. action of testosterone on mesenchyme cell.
A
19. Invaginations of the muscle cell membrane that extend deep into the cell are known as the A. T-tubules. B. terminal cisternae. C. titin complexes. D. Z-discs. E. end plates.
A
21. Which protein makes up the thick filaments? A. Myosin B. Actin C. Tropomyosin D. Troponin E. Myopathy
A
24. A skeletal muscle cell contains hundreds to thousands of _________, which are complex organelles, they are cylindrical in shape—about 2 micrometers in diameter and as long as the cell. A. myofibrils B. microfilaments C. sarcomeres D. T-tubules E. sarcolemma
A
28. Which letter is associated with the light band and contains thin filaments only? A. I B. A C. M D. Z E. H
A
29. Which of the following structures has the active sites to which the heads of the thick filaments will bind? A. Actin B. Troponin C. Tropomyosin D. Myosin E. Sarcoplasm
A
51. Which sequence correctly lists the changes that allow the thick and thin filaments to slide past one another in skeletal muscle contraction? A. Attach - pivot - detach - return B. Pivot - attach - return - detach C. Attach - detach - pivot - return D. Return - pivot - attach - detach E. Pivot - attach - detach - return
A
55. For relaxation to occur, A. ACh receptors close and Ca++ channels on the sarcoplasmic reticulum close. B. ACh receptors close and Ca++ channels on the sarcoplasmic reticulum open. C. ACh receptors open and Ca++ channels on the sarcoplasmic reticulum close. D. ACh receptors open and Ca++ channels on the sarcoplasmic reticulum open.
A
74. The vascular supply to slow-twitch muscle fibers is ______ the network of capillaries around fast-twitch muscle fibers. A. more extensive than B. less extensive than C. the same as that of
A
77. Muscles of the eye and hand have a high percentage of _______ fibers. A. fast-twitch B. Slow-twitch
A
8. Which is a correct listing of the hierarchy of a skeletal muscle's components, beginning with the smallest? a: Myofibrils b: Muscle fiber c: Fascicle d: Skeletal muscle A. a, b, c, d B. a, c, b, d C. d, c, b, a D. c, b, a, d E. b, c, a, d
A
84. 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.
A
81. A subthreshold stimulus evokes only a small muscle twitch instead of a full tetanic contraction.
FALSE
85. Consider the difference between lifting a light pad of paper versus a heavy textbook. The primary way the level of force of muscle contraction is controlled is by A. recruiting a different number of motor units. B. activating different regions of the muscle. C. activating the motor units at a different frequency. D. altering the number of crossbridges each individual fiber uses.
A
87. In a graph of wave summation, the tension level returns to baseline between each peak of force.
FALSE
104. 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.
B
107. Growth of the uterus during pregnancy is accomplished by _________ of its smooth muscle. A. neither hypertrophy nor hyperplasia B. both hypertrophy and hyperplasia C. hypertrophy but not hyperplasia D. hyperplasia but not hypertrophy
B
111. 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.
B
117. Smooth muscle tissue in which cells are individually sent signals to contract (rather than contracting in unison) is referred to as A. single-unit. B. multiunit.
B
118. The iris of the eye contains A. skeletal muscle. B. multiunit smooth muscle. C. single-unit smooth muscle. D. cardiac muscle.
B
133. The type of muscle fibers that are striated, form Y-shaped branches, and are joined by intercalated discs are A. skeletal. B. cardiac. C. smooth. D. voluntary. E. skeletal and voluntary.
B
25. What is the letter associated with the dark bands in a sarcomere? A. I B. A C. Z D. M E. H
B
32. Myoglobin is a molecule within muscle cells that can bind A. creatine phosphate. B. oxygen. C. hemoglobin. D. acetylcholine. E. ATP.
B
36. A motor unit consists of A. multiple motor neurons and multiple muscle fibers. B. a single motor neuron and the multiple muscle fibers it controls. C. multiple motor neurons and the one muscle fiber they control. D. one synaptic terminal button, a cleft, and an acetylcholine receptor. E. an end plate, a T-tubule, and sarcoplasmic reticulum.
B
39. Fibers from one motor unit A. are clustered together within one fascicle of the muscle. B. are dispersed throughout most of the muscle.
B
43. When an impulse arrives at the knob of the motor neuron, calcium A. enters through active transport pumps and triggers the release of transmitter. B. enters through voltage-gated channels and triggers the release of transmitter. C. exits through active transport pumps and brings transmitter with it. D. exits through voltage-gated channels and triggers transmitter release. E. is released from synaptic vesicles.
B
45. Acetylcholine exerts its effect by A. stimulating the motor neuron's synaptic knob. B. binding to receptors at the motor end plate. C. activating acetylcholinesterase. D. allowing calcium to enter the cell.
B
48. An end plate potential is an event that involves a gain of A. positive charge along the inside of the cell membrane, as potassium rapidly enters. B. positive charge along the inside of the cell membrane, as sodium rapidly enters. C. negative charge along the inside of the cell membrane, as potassium rapidly enters. D. negative charge along the inside of the cell membrane, as sodium rapidly enters.
B
49. The action potential of a muscle fiber occurs A. at the end plate. B. along the sarcolemma and down the T-tubules. C. within the sarcoplasmic reticulum. D. in the mitochondria.
B
54. A drug that inhibited acetylcholinesterase would result in A. a failure to stimulate the muscle due to decreased ACh release. B. enhanced stimulation of the muscle due to decreased ACh breakdown. C. enhanced stimulation of the muscle due to enhanced ACh release. D. poor muscle stimulation due to enhanced ACh breakdown.
B
86. "Staircase" and "warming-up effect" refer to ___________, an increased muscle response to a constant stimulus. A. wave summation B. treppe C. multiple motor unit summation D. incomplete tetany E. isotony
B
96. 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.
B
100. Increased phosphate ion concentration is believed to contribute to fatigue by interfering with A. calcium release from the sarcoplasmic reticulum. B. levels of available ATP to provide energy for contraction. C. phosphate release by myosin heads during crossbridge cycling. D. ACh release by synaptic knobs of motor neurons.
C
106. 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.
C
110. The latchbridge mechanism of myosin heads is a property of ________ muscle. A. cardiac B. skeletal C. smooth
C
120. Rather than tightly coupled synapses between neurons and muscle cells, single-unit smooth muscle contains A. gap junctions that connect neurons to smooth muscle cells. B. varicosities of a subset of muscle fibers so that individual cells can be separately stimulated. C. diffuse junctions where neuron varicosities are responsible for neurotransmitter release. D. plaques and caveolae that contain multiple hormone receptors for discrete endocrine control.
C
23. Each thick filament contains about ______ protein molecules (each molecule has two heads and two braided tails). A. 2 B. 20 C. 200 D. 2000
C
26. Which letter is associated with the line that is a thin protein structure that serves as an attachment site for thin filament ends? A. I B. A C. Z D. M E. H
C
35. One feature that helps provide fast energy to a muscle cell is the presence of granules containing the complex carbohydrate A. creatine phosphate. B. myoglobin. C. glycogen. D. nebulin. E. hemoglobin.
C
40. The narrow space that separates the motor neuron and the skeletal muscle fiber in a neuromuscular junction is called the A. motor end plate. B. synaptic vesicle. C. synaptic cleft. D. synaptic knob.
C
52. During which phase of the crossbridge cycle is ATP split into ADP and Pi? A. Immediately preceding the detachment of the myosin head B. Immediately preceding the resetting of the myosin head C. Immediately preceding the power stroke 53. A power stroke involves A. an actin molecule pulling a myosin molecule toward the M-line. B. a thin filament shortening in length and thereby shortening the sarcomere. C. a myosin head pulling a thin filament toward the center of the sarcomere. D. a thick filament pushing an actin filament towards the nearest Z-line.
C
56. For relaxation to occur, A. calcium leaves the sarcoplasmic reticulum, and troponin binds calcium and blocks the binding sites on actin. B. calcium enters the myofibril, it detaches from myosin, and the binding sites on myosin become inactive. C. sarcoplasm calcium levels fall, calcium is removed from troponin, and tropomyosin blocks binding sites on actin. D. extracellular calcium levels fall, calcium is pumped into the myofibril, and tropomyosin slides away from actin.
C
57. When a muscle relaxes, A. crossbridges form and muscle extensibility returns the muscle to rest length. B. crossbridges form and muscle elasticity returns the muscle to rest length. C. crossbridges stop forming and muscle elasticity returns the muscle to rest length. D. crossbridges stop forming and muscle extensibility returns the muscle to rest length
C
61. Glycolysis is an A. aerobic process that occurs in the cytosol. B. aerobic process that occurs in the mitochondria. C. anaerobic process that occurs in the cytosol. D. anaerobic process that occurs in the mitochondria.
C
80. 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
C
82. Release of crossbridges and a decline in muscle tension characterize the _______ period of a twitch. A. contraction B. latent C. relaxation
C
95. The most prevalent of skeletal muscle fibers in the body are _____ fibers. A. slow-twitch B. fast-twitch C. intermediate
C
41. The neuromuscular junction is usually located at one of the two ends of the muscle fiber.
FALSE
60. Myosin kinase catalyzes the transfer of Pi from creatine phosphate to ADP.
FALSE
12. The neurons that stimulate muscle contraction are called _____ neurons. A. sensory B. contractile C. inhibitory D. motor E. association
D
38. A motor unit within the powerful quadriceps muscle would A. contain several motor neurons. B. be much like those in the eye muscles. C. generally contain less than ten fibers. D. generally contain several hundred fibers.
D
31. __________ is a protein that anchors myofibrils that are adjacent to the sarcolemma to proteins in the sarcolemma.
Dystrophin
101. Which may occur as a result of muscle atrophy? A. Reduction in muscle size B. Fibers become weaker C. Muscle loses tone D. Fibers waste away and die E. All of the choices are correct.
E
2. Which are possible functions of skeletal muscles? a: Maintenance of posture b: Both highly coordinated and localized simple movements c: Temperature regulation d: Support of certain body organs e: Regulation of the movement of material through certain body tracts A. a, b, e B. a, b, c C. a, b, c, e D. a, b, c, d E. a, b, c, d, e
E
27. Which letter is associated with a zone (in a relaxed muscle) that is a little more lightly shaded because only thick filaments are present? A. I B. A C. M D. Z E. H
E
66. If someone is engaged in six minutes of vigorous exercise, nearly all of the ATP used is generated by phosphate transfer.
FALSE
47. The calcium ions involved in skeletal muscle contraction bind to a(n)______ subunit. A. myosin B. actin C. elastin D. tropomyosin E. troponin
E
7. In general, a skeletal muscle is composed of a: connective tissue sheaths b: nerves c: arteries d: veins e: muscle fibers A. a, b, c, e B. a, b, d, e C. b, c, d, e D. a, b, c, d E. a, b, c, d, e
E
69. In general, fast-twitch fibers generate less power than slow-twitch fibers.
FALSE
72. Glycolytic muscle fibers tend to be very rich in myoglobin and mitochondria.
FALSE
113. Energy requirements for smooth muscle contractions are generally higher than those for skeletal muscle contractions.
FALSE
115. Similar to skeletal muscle cells, all smooth muscle cells are excited by ACh.
FALSE
124. The fat and connective tissue that encircle a beef steak form the endomysium.
FALSE
128. The return of a contracted muscle fiber to its resting length is an active (energy requiring) process.
FALSE
132. The metabolic reactions within fast-twitch fibers derive much of their energy from aerobic respiration.
FALSE
37. Muscles that are used for precisely controlled movements generally contain large motor units.
FALSE
112. 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.
TRUE
125. The T-tubules and sarcoplasmic reticulum are unique to muscle fibers.
TRUE
126. The embryonic-like cells that remain in adult skeletal muscle tissue are known as satellite cells.
TRUE
127. During skeletal muscle fiber contraction, the I bands and H zones narrow.
TRUE
129. During skeletal muscle contraction, more force is created when more motor units are activated.
TRUE
13. Deep fascia is also known as muscular fascia, it is composed of dense irregular connective tissue.
TRUE
130. In an isotonic contraction, the tension produced exceeds the resistance and muscle fibers will shorten.
TRUE
131. Slow-twitch fibers are specialized to continue contracting for extended periods of time without experiencing fatigue.
TRUE
134. Cardiac muscle cells tend to be thicker and shorter than skeletal muscle cells.
TRUE
135. The number of satellite cells in skeletal muscle steadily decreases with age.
TRUE
136. Smooth muscle tissue is found in the organs of the digestive tract, the walls of blood vessels, and the iris.
TRUE
153. When a skeletal muscle fiber is at rest, there is more sodium outside the cell as compared to the sarcoplasm.
TRUE
16. The connections between the nervous system and skeletal muscle allow for voluntary control of movement.
TRUE
3. The floor of the pelvic cavity includes skeletal muscles that function to support organs in that cavity.
TRUE
63. Aerobic respiration involves the oxidation of pyruvate.
TRUE
68. Heavy breathing to compensate for an oxygen debt helps the body convert lactate to glucose.
TRUE
70. Compared to slow-twitch fibers, fast-twitch fibers respond to a stimulus with less delay and with a shorter contraction duration.
TRUE
58. Relaxation is facilitated by the release of passive tension that developed in cablelike __________ proteins that were compressed during contraction.
connectin
83. A graph of a muscle twitch contains three periods. The period during which there is no change in external muscle tension (and no change in muscle length) is the ________ period.
latent
109. Within smooth muscle cells, intermediate filaments are linked by dense _________ at points where they attach on the inner surface of the cell membrane.
plaques