Fundamentals of Anatomy & Physiology, 10E, GE (Martini)

Fundamentals of Anatomy & Physiology, 10e, GE (Martini) Chapter 10 Muscle Tissue

Multiple Choice Questions: Section One

1) Muscle tissue, one of the four basic tissue groups, consists chiefly of cells that are highly specialized for A) conduction. B) contraction. C) peristalsis. D) cushioning. E) secretion. Answer: B Learning Outcome: 10-1 Bloom's Taxonomy: Knowledge

2) Which of the following is a recognized function of skeletal muscle? A) produce movement B) maintain posture C) maintain body temperature D) guard body entrances and exits E) All of the answers are correct. Answer: E Learning Outcome: 10-1 Bloom's Taxonomy: Knowledge

3) At each end of the muscle, the collagen fibers of the epimysium, perimysium, and endomysium, come together to form a A) tendon. B) satellite cell. C) ligament. D) tenosynovium. E) sheath. Answer: A Learning Outcome: 10-2 Bloom's Taxonomy: Knowledge

4) The dense layer of connective tissue that surrounds an entire skeletal muscle is the A) tendon. B) epimysium. C) endomysium. D) perimysium. E) fascicle. Answer: B Learning Outcome: 10-2 Bloom's Taxonomy: Knowledge

1 Copyright © 2015 Pearson Education, Inc. 5) Nerves and blood vessels that service a muscle fiber are located in the connective tissues of its A) endomysium. B) perimysium. C) sarcolemma. D) sarcomere. E) myofibrils. Answer: A Learning Outcome: 10-2 Bloom's Taxonomy: Knowledge

6) A fascicle is a A) group of muscle fibers that are encased in the perimysium. B) layer of connective tissue that separates muscle from skin. C) group of muscle fibers that are all part of the same motor unit. D) group of muscle fibers and motor neurons. E) collection of myofibrils in a muscle fiber. Answer: A Learning Outcome: 10-2 Bloom's Taxonomy: Knowledge

7) The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the A) endomysium. B) perimysium. C) epimysium. D) superficial fascia. E) periosteum. Answer: A Learning Outcome: 10-2 Bloom's Taxonomy: Knowledge

8) The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a(n) A) fascicle. B) tendon. C) ligament. D) epimysium. E) myofibril. Answer: B Learning Outcome: 10-2 Bloom's Taxonomy: Knowledge

2 Copyright © 2015 Pearson Education, Inc. 9) Put the following structures in order from superficial to deep. 1. muscle fiber 2. perimysium 3. myofibril 4. fascicle 5. endomysium 6. epimysium A) 1, 5, 4, 3, 2, 6 B) 6, 2, 5, 4, 1, 3 C) 6, 2, 4, 5, 1, 3 D) 1, 3, 5, 6, 4, 2 E) 2, 3, 1, 4, 6, 5 Answer: C Learning Outcome: 10-2 Bloom's Taxonomy: Comprehension

10) Interactions between actin and myosin filaments of the sarcomere are responsible for A) muscle fatigue. B) the conduction of neural stimulation to the muscle fiber. C) muscle contraction. D) muscle relaxation. E) the striped appearance of skeletal muscle. Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

11) In a sarcomere, the central portion of thick filaments are linked laterally by proteins of the A) Z line. B) M line. C) H band. D) A band. E) I band. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

12) The advantage of having many nuclei in a skeletal muscle fiber is the ability to A) contract much more forcefully. B) produce more ATP with little oxygen. C) store extra DNA for metabolism. D) produce large amounts of muscle proteins. E) produce nutrients for muscle contraction. Answer: D Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

3 Copyright © 2015 Pearson Education, Inc. 13) Skeletal muscle fibers are formed from embryonic cells called A) sarcomeres. B) myofibrils. C) myoblasts. D) fascicles. E) myomeres. Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

14) The repeating unit of a skeletal muscle fiber is the A) sarcolemma. B) sarcomere. C) sarcoplasmic reticulum. D) myofibril. E) myofilament. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

15) The plasma membrane of a skeletal muscle fiber is called the A) sarcolemma. B) sarcomere. C) sarcosome. D) sarcoplasmic reticulum. E) sarcoplasm. Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

16) Which of the following best describes the term sarcomere? A) protein that accounts for elasticity of resting muscle B) repeating unit of striated myofibrils C) storage site for calcium ions D) thin filaments are anchored here E) largely made of myosin molecules Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

4 Copyright © 2015 Pearson Education, Inc. 17) Muscle fibers differ from "typical cells" in that muscle fibers A) lack a plasma membrane. B) have many nuclei. C) are very small. D) lack mitochondria. E) have large gaps in the cell membrane. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

18) Which of the following best describes the term sarcoplasmic reticulum? A) protein that accounts for elasticity of resting muscle B) repeating unit of striated myofibrils C) storage and release site for calcium ions D) thin filaments are anchored here E) largely made of myosin molecules Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

19) Which of the following best describes the term Z line? A) protein that accounts for elasticity of resting muscle B) repeating unit of striated myofibrils C) storage site for calcium ions D) thin filaments are anchored here E) largely made of myosin molecules Answer: D Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

20) The region of the sarcomere containing the thick filaments is the A) Z line. B) M line. C) H band. D) A band. E) I band. Answer: D Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

5 Copyright © 2015 Pearson Education, Inc. 21) The skeletal muscle complex known as the triad consists of A) actin, myosin, and titin filaments. B) a transverse tubule and two terminal cisternae. C) filaments, myofibrils, and sarcomeres. D) A bands, H bands, and I bands. E) actin, myosin, and sarcomeres. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

22) Cross-bridges are portions of A) actin molecules. B) myosin molecules. C) troponin molecules. D) tropomyosin molecules. E) calcium ions. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

23) The area in the center of the A band that contains no thin filaments is the A) Z line. B) M line. C) H band. D) I band. E) zone of overlap. Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

24) Each skeletal muscle fiber contains ______myofibrils. A) 50 to 100 B) 100 to 150 C) 150 to 200 D) 200 to 500 E) hundreds to thousands Answer: E Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

6 Copyright © 2015 Pearson Education, Inc. 25) At rest, the tropomyosin molecule is held in place by A) actin molecules. B) myosin molecules. C) troponin molecules. D) ATP molecules. E) calcium ions. Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

26) Each thin filament consists of A) two actin protein strands coiled helically around each other. B) chains of myosin molecules. C) six molecules coiled into a helical structure. D) a rod-shaped structure with "heads" projecting from each end. E) a double strand of myosin molecules. Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

27) Which of the following best describes the term titin? A) protein that accounts for elasticity of resting muscle B) repeating unit of striated myofibrils C) storage and release site for calcium ions D) thin filaments are anchored here E) largely made of myosin molecules Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

28) The region of the sarcomere that always contains thin filaments is the A) Z line. B) M line. C) H band. D) A band. E) I band. Answer: E Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

7 Copyright © 2015 Pearson Education, Inc. 29) At rest, active sites on the actin are blocked by A) myosin molecules. B) troponin molecules. C) tropomyosin molecules. D) calcium ions. E) ATP molecules. Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

30) The series of membranous channels that surround each myofibril is the A) sarcoplasmic reticulum. B) sarcoplasm. C) sarcomere. D) sarcolemma. E) endomysium. Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

31) Which of the following statements about the microscopic anatomy of skeletal muscle fibers is false? A) Tubular extensions of the sarcolemma penetrate the fiber transversely. B) Cross striations result from the lateral alignment of thick and thin filaments. C) Each fiber has many nuclei to ensure adequate muscle protein production. D) The net-like sarcoplasmic reticulum surrounds each myofilament. E) All of the answers are true; there are no false answers. Answer: D Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

32) All of the following proteins are part of the thin filaments except A) actin. B) tropomyosin. C) troponin. D) titin. E) None of the answers is correct; there are no exceptions. Answer: D Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

8 Copyright © 2015 Pearson Education, Inc. 33) When a skeletal muscle fiber contracts, the A) H bands and I bands get larger. B) zones of overlap get larger. C) Z lines move further apart. D) width of the A band increases. E) All of the answers are correct. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

34) Since each myofibril is attached at either end of the muscle fiber, when sarcomeres shorten, the muscle fiber A) lengthens. B) shortens. C) strengthens. D) weakens. E) pulls from the middle. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Application

Use Figure 10-1 to answer the following questions:

35) Identify the structure labeled "1." A) mitochondria B) glycogen C) ATP D) myofibril E) synaptic vesicle Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

36) Which of the following are found in the structure labeled "3"? A) actin B) myosin C) titin D) tropomyosin E) All of the answers are correct. Answer: E Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

37) What physiological process occurs in the structure labeled "7"? A) release of neurotransmitter B) conduction of the action potential into the cell interior C) activity of acetylcholinesterase D) release of protein and calcium ions into the muscle fiber E) opening of sodium channels and subsequent influx of sodium Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension 10 Copyright © 2015 Pearson Education, Inc. 38) What is released from the structure labeled "9"? A) sarcoplasm B) acetylcholine C) protein D) calcium ions E) acetylcholinesterase Answer: D Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

39) Where would calcium ions be predominately found? A) 1 B) 2 C) 4 D) 8 E) 9 Answer: E Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

40) Which structure has pumps to remove calcium ions from the sarcoplasm to produce relaxation? A) 6 B) 7 C) 1 D) 3 E) 2 Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

41) Where are the myosin molecules located? A) 4 B) 5 C) 6 D) 7 E) 8 Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

43) Identify the structure where ATP is produced. A) 6 B) 7 C) 1 D) 3 E) 2 Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

44) Identify the structure(s) where ATP is consumed? A) 3 B) 6 C) 3 and 6 D) 7 E) 3 and 7 Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Comprehension

45) In response to action potentials arriving along the transverse tubules, the sarcoplasmic reticulum releases A) acetylcholine. B) sodium ions. C) potassium ions. D) calcium ions. E) hydrogen ions. Answer: D Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

12 Copyright © 2015 Pearson Education, Inc. 46) Each skeletal muscle fiber is controlled by a motor neuron at a single A) synaptic knob. B) sarcomere. C) neuromuscular junction. D) synaptic cleft. E) transverse tubule. Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

47) The narrow space between the synaptic terminal and the muscle fiber is the A) synaptic knob. B) motor end plate. C) motor unit. D) synaptic cleft. E) M line. Answer: D Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

48) Active sites on the actin become available for binding after A) actin binds to troponin. B) troponin binds to tropomyosin. C) calcium binds to troponin. D) calcium binds to tropomyosin. E) myosin binds to troponin. Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

49) Receptors for acetylcholine are located on the A) synaptic knob. B) motor end plate. C) sarcomere. D) synaptic cleft. E) transverse tubule. Answer: B Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

13 Copyright © 2015 Pearson Education, Inc. 50) The action potential is conducted into a skeletal muscle fiber by A) motor end plates. B) neuromuscular junctions. C) transverse tubules. D) triads. E) sarcoplasmic reticulum. Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

51) The most important factor in decreasing the intracellular concentration of calcium ion after contraction is A) active transport of calcium across the sarcolemma. B) active transport of calcium into the sarcoplasmic reticulum. C) active transport of calcium into the synaptic cleft. D) diffusion of calcium out of the cell. E) diffusion of calcium into the sarcoplasmic reticulum. Answer: B Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

52) Which of the following acts as an ATPase during the contraction cycle of muscle? A) actin molecules B) troponin molecules C) tropomyosin molecules D) the head portion of the myosin molecule E) the tail portion of the myosin molecule Answer: D Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

53) When calcium ion binds to troponin, A) tropomyosin rolls away from the active site. B) active sites on the myosin are exposed. C) actin heads will bind to myosin. D) muscle relaxation occurs. E) myosin shortens. Answer: A Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

14 Copyright © 2015 Pearson Education, Inc. 54) Which of the following become connected by myosin cross-bridges during muscle contraction? A) thin filaments and thick filaments B) thick filaments and titin filaments C) z disks and actin filaments D) thick filaments and t-tubules E) thin filaments and t-tubules Answer: A Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

55) After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as A) tetany. B) treppe. C) depolarization. D) rigor mortis. E) oxygen debt. Answer: D Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

56) In rigor mortis A) the myosin heads are attached to actin. B) ATP is depleted. C) calcium ions keep binding to troponin. D) sustained contractions occur. E) All of the answers are correct. Answer: E Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

57) In a sarcomere, cross-bridge attachment occurs specifically in the A) zone of overlap. B) A band. C) I band. D) M line. E) H band. Answer: A Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

15 Copyright © 2015 Pearson Education, Inc. 58) Physical evidence that supports the sliding filament theory of muscle contraction includes A) constant distance between Z lines during contraction. B) decreased width of the H band during contraction. C) increased width of the I band during contraction. D) decreased width of the A band during contraction. E) the I band + H band distance is constant during contraction. Answer: B Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

59) Triggering of the muscle action potential occurs after A) acetylcholine binds to chemically-gated channels in the motor end plate. B) acetylcholinesterase is released from synaptic vesicles into the synaptic cleft. C) calcium ion binds to channels on the motor end plate. D) the action potential jumps across the neuromuscular junction. E) Any of these can produce an action potential in the muscle cell. Answer: A Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

60) The following is a list of the events that occur during a muscle contraction. What is the correct sequence of these events? 1. Myosin cross-bridges bind to the actin. 2. The free myosin head splits ATP. 3. Calcium ion is released from the sarcoplasmic reticulum. 4. The myosin head pivots toward the center of the sarcomere. 5. Calcium ion binds to troponin. 6. The myosin head binds an ATP molecule and detaches from the actin. A) 1, 3, 5, 4, 6, 2 B) 5, 1, 4, 6, 2, 3 C) 3, 5, 1, 2, 4, 6 D) 3, 5, 1, 4, 6, 2 E) 1, 4, 6, 2, 3, 5 Answer: D Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

61) How would the loss of acetylcholinesterase from the motor end plate affect skeletal muscle? A) It would make the muscles less excitable. B) It would produce muscle weakness. C) It would cause muscles to stay contracted. D) It would cause muscles to stay relaxed. E) It would have little effect on skeletal muscles. Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

16 Copyright © 2015 Pearson Education, Inc. 62) When acetylcholine binds to receptors at the motor end plate, the sarcolemma becomes A) more permeable to sodium ions. B) less permeable to sodium ions. C) more permeable to calcium ions. D) less permeable to potassium ions. E) less permeable to potassium and sodium ions. Answer: A Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

63) The cytoplasm of the neuromuscular terminal contains vesicles filled with molecules of the neurotransmitter A) epinephrine. B) norepinephrine. C) acetylcholine. D) antidiuretic hormone. E) adrenaline. Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

64) At what point during excitation contraction coupling does exocytosis play a role? A) during calcium ion reuptake into the sarcoplasmic reticulum B) when sodium channels open up on the motor end plate C) during acetylcholine release from the synaptic terminal D) when the action potential surges through the T-tubules E) when ATP splits into ADP and P on the free myosin head Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

65) Which of the following statements about excitation-contraction coupling is incorrect? A) Calcium ions travel through the transverse tubule. B) Calcium ion is released from the sarcoplasmic reticulum. C) Tropomyosin moves to expose myosin binding sites on actin. D) Troponin binds calcium ion and signals tropomyosin to move. E) Relaxation requires uptake of calcium ion by the sarcoplasmic reticulum. Answer: A Learning Outcome: 10-4 Bloom's Taxonomy: Application

17 Copyright © 2015 Pearson Education, Inc. 66) Synaptic vesicles contain neurotransmitters that are released by ______when the action potential arrives. A) endocytosis B) apoptosis C) exocytosis D) hydrolysis E) sodium Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Application

67) The muscle weakness of myasthenia gravis results from A) insufficient acetylcholine release from presynaptic vesicles. B) loss of acetylcholine receptors in the end-plate membrane. C) the motor neuron action potential being too small to stimulate the muscle fibers. D) excessive acetylcholinesterase that destroys the neurotransmitter. E) inability of the muscle fiber to produce ATP. Answer: B Learning Outcome: 10-4 Bloom's Taxonomy: Application

68) A patient takes a medication that blocks ACh receptors of skeletal muscle fibers. What is this drug's effect on skeletal muscle contraction? A) increases tone in the muscle B) causes a strong contraction similar to a "charlie horse" cramp C) increases the muscle's excitability D) produces a strong, continuous state of contraction E) reduces the muscle's ability for contraction Answer: E Learning Outcome: 10-4 Bloom's Taxonomy: Application

69) The rapid rise and fall in force produced by a muscle fiber after a single action potential is a(n) A) tetanus. B) unfused tetanus. C) twitch. D) motor end plate potential. E) muscle action potential. Answer: C Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

18 Copyright © 2015 Pearson Education, Inc. 70) When a muscle is stimulated repeatedly at a high rate, the amount of tension gradually increases to a steady maximum tension. This state of maximum tension is called A) incomplete tetanus. B) complete tetanus. C) a twitch. D) wave summation. E) recruitment. Answer: B Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

71) A muscle producing almost peak tension during rapid cycles of contraction and relaxation is said to be in A) incomplete tetanus. B) complete tetanus. C) treppe. D) wave summation. E) recruitment. Answer: A Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

72) If a second stimulus arrives before the relaxation phase has ended, a second, more powerful contraction occurs. This addition of one twitch to another is called A) incomplete tetanus. B) complete tetanus. C) treppe. D) wave summation. E) recruitment. Answer: D Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

73) A single motor neuron together with all the muscle fibers it innervates is called a(n) A) end foot. B) end plate. C) motor unit. D) dermatome. E) myotome. Answer: C Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

19 Copyright © 2015 Pearson Education, Inc. 74) The contraction of a muscle exerts a pull on a bone because muscles attach to bones by A) ligaments. B) bursae. C) tendons. D) fasciae. E) myofibrils. Answer: C Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

75) The increase in muscle tension that is produced by increasing the number of active motor units is called A) incomplete tetanus. B) complete tetanus. C) treppe. D) wave summation. E) recruitment. Answer: E Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

76) The type of contraction in which the muscle fibers do not shorten is called A) tetany. B) treppe. C) concentric. D) isotonic. E) isometric. Answer: E Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

77) A weight-lifter strains to lift a heavy weight and there is no movement of the person's arms holding on to the weight. This type of contraction is called a(n) ______contraction. A) isometric B) tetanus C) isotonic D) treppe E) concentric Answer: A Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

20 Copyright © 2015 Pearson Education, Inc. 78) You try to pick up an object and discover that it is much heavier than you expected. Which process must occur in the muscle to increase tension so you can pick up the object? A) wave summation B) isotonic contraction C) complete tetanus D) recruitment E) treppe Answer: D Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

79) In which of the following would the motor units have the fewest muscle fibers? A) muscles of the neck B) postural muscles of the back C) muscles that control the eyes D) thigh muscles E) calf muscles Answer: C Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

80) In an isotonic contraction, A) muscle tension exceeds the load and the muscle lifts the load. B) tension rises and falls but the muscle length is constant. C) the peak tension is less than the load. D) many twitches always fuse into one. E) postural muscles stabilize the vertebrae. Answer: A Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

Use Figure 10-2 to answer the following questions:

81) What is the contraction in graph (a) called? A) complete tetanus B) incomplete tetanus C) twitch D) wave summation E) treppe Answer: E Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

82) What is thought to happen in a muscle during the response shown in graph (a)? A) It is strengthening with exercise. B) There is a gradual increase in calcium ion concentration in the sarcoplasm. C) It is fatigued and must make repeated efforts to twitch normally. D) It is aged and has lost contractile proteins. E) It is producing more ATP as tension increases. Answer: B Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

22 Copyright © 2015 Pearson Education, Inc. 83) To produce a contraction similar to the one in graph (b), the muscle A) must be stimulated to the point of fatigue. B) must be stimulated again before it has relaxed from the previous stimulation. C) is excited by a stimulus of increasing intensity. D) must go through a rapid series of isolated twitches. E) generates more and more thin and thick filaments. Answer: B Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

84) Why is there partial relaxation in graph (c)? A) Calcium ion release is slow. B) The muscle is starting to fatigue. C) Stimulation intensity is fluctuating. D) ATP reserves are cycling. E) Nerve stimulation frequency is below maximum. Answer: E Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

85) What is the contraction in graph (d) called? A) complete tetanus B) incomplete tetanus C) twitch D) wave summation E) treppe Answer: A Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

86) In the liver, during the Cori cycle, A) glucose is released from glycogen. B) lactic acid is produced from glucose. C) glucose is produced from lactic acid. D) lactic acid is produced from pyruvic acid. E) lactic acid is shuffled to muscle cells. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

23 Copyright © 2015 Pearson Education, Inc. 87) During the recovery period the body's need for oxygen is increased because A) muscle cells are producing ATP anaerobically. B) creatine phosphate stimulates mitochondrial activity. C) additional oxygen is required to restore energy reserves. D) the liver requires more oxygen to produce lactic acid. E) the muscles produce much less ATP. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

88) A resting muscle generates most of its ATP by A) hydrolysis of creatine phosphate. B) anaerobic respiration. C) aerobic metabolism of fatty acids. D) glycogenolysis. E) the tricarboxylic acid cycle. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

89) Creatine phosphate A) is produced by the process of anaerobic respiration. B) can replace ATP in binding to myosin molecules during contraction. C) acts as an energy reserve in muscle tissue. D) is only formed during strenuous exercise. E) cannot transfer its phosphate group to ADP. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

90) During anaerobic glycolysis, A) ATP is produced. B) pyruvic acid is produced. C) oxygen is not consumed. D) carbohydrate is metabolized. E) All of the answers are correct. Answer: E Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

24 Copyright © 2015 Pearson Education, Inc. 91) Aerobic metabolism normally provides ______percent of the ATP demands of a resting muscle cell. A) 25 B) 50 C) 70 D) 95 E) 100 Answer: D Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

92) After heavy exercise, if energy reserves in a muscle are depleted, ______occurs. A) an oxygen debt B) paralysis C) treppe D) tetanus E) atrophy Answer: A Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

93) During the recovery period following exercise, all of the following are true except A) lactic acid is removed from muscle cells. B) the muscle actively produces ATP. C) muscle fibers are unable to contract. D) oxygen is consumed at above the resting rate. E) heat is generated. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Comprehension

94) At peak levels of muscle exertion the mitochondria can supply A) all of the energy required by the muscle. B) 80 percent of the energy required by the muscle. C) more than half of the energy required by the muscle. D) only about one-third of the energy required by the muscle. E) only about 10 percent of the energy required by the muscle. Answer: D Learning Outcome: 10-6 Bloom's Taxonomy: Knowledge

25 Copyright © 2015 Pearson Education, Inc. 95) Which of the following hormones directly stimulates growth of muscle tissue, leading to increased muscle mass? A) epinephrine B) thyroid hormone C) testosterone D) parathyroid hormone E) calcitonin Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Comprehension

96) Which of the following would not lead to increased oxygen consumption? A) increased heat production B) increased conversion of lactic acid to glucose C) increased anaerobic respiration by muscle cells D) increased muscle activity E) All of the answers are correct; none would lead to increased oxygen consumption. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Comprehension

97) Because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have A) a rich nerve supply to ensure a rapid succession of action potentials. B) massive creatine phosphate reserves for long periods of sustained contractions. C) extra calcium reserves which can serve as fuel molecules during ATP synthesis. D) adipose tissue between fibers to supply nutrients for ATP production. E) many mitochondria and a rich blood supply. Answer: E Learning Outcome: 10-6 Bloom's Taxonomy: Comprehension

98) Decreased blood flow to a muscle could result in all of the following except A) muscle fatigue. B) an oxygen debt. C) an increase in intracellular glycogen. D) a shift to anaerobic glycolysis. E) an increase in intracellular lactic acid. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Comprehension

26 Copyright © 2015 Pearson Education, Inc. 99) How would an elevated level of thyroid hormone in the body affect skeletal muscles? A) It would stimulate atrophy. B) It would stimulate hypertrophy. C) It would stimulate energy use and heat production. D) It would decrease heat production by muscle tissue. E) It would cause an increase in muscle mass. Answer: C Learning Outcome: 10-6 Bloom's Taxonomy: Comprehension

100) Heat energy gained from muscle contraction is released by the ______system. A) integumentary B) respiratory C) cardiovascular D) urinary E) endocrine Answer: A Learning Outcome: 10-6 Bloom's Taxonomy: Comprehension

101) The type of muscle fiber that is most resistant to fatigue is the ______fiber. A) fast B) slow C) intermediate D) anaerobic E) high-density Answer: B Learning Outcome: 10-7 Bloom's Taxonomy: Knowledge

102) Fast fibers A) have low resistance to fatigue. B) rely on aerobic metabolism. C) have many mitochondria. D) have twitches with a very brief contraction phase. E) have low resistance to fatigue and quick twitches. Answer: E Learning Outcome: 10-7 Bloom's Taxonomy: Knowledge

27 Copyright © 2015 Pearson Education, Inc. 103) Muscles that move the eyeball have ______fibers. A) fast B) slow C) intermediate D) circular E) All of the answers are correct. Answer: A Learning Outcome: 10-7 Bloom's Taxonomy: Comprehension

104) During activities requiring aerobic endurance, A) glycogen and glycolysis are the primary sources of reserve energy. B) oxygen debts are common. C) most of the muscle's energy is produced in mitochondria. D) fatigue occurs in a few minutes. E) oxygen is not required. Answer: C Learning Outcome: 10-7 Bloom's Taxonomy: Knowledge

105) Fast muscle fibers can adapt to aerobic metabolism by generating more mitochondria in response to A) repeated, exhaustive stimulation. B) sustained low levels of muscle activity. C) high amounts of oxygen. D) increased levels of testosterone. E) prolonged periods of inactivity. Answer: A Learning Outcome: 10-7 Bloom's Taxonomy: Comprehension

106) Which of the following statements is/are false regarding human muscles? A) Most have both slow and fast fibers. B) Slow fibers are abundant in the muscles of the hand. C) Eye muscles are composed entirely of fast fibers. D) Slow fibers are abundant in the back muscles. E) All of the answers are correct; none of them are true regarding human muscles. Answer: B Learning Outcome: 10-7 Bloom's Taxonomy: Comprehension

28 Copyright © 2015 Pearson Education, Inc. 107) When comparing slow muscle fibers to fast muscle fibers, slow fibers A) take about three times as long to reach peak tension. B) have much smaller fiber diameters. C) generate much less tension. D) are rich in the red protein myoglobin. E) All of the answers are correct. Answer: E Learning Outcome: 10-7 Bloom's Taxonomy: Knowledge

108) Large-diameter, densely packed myofibrils, large glycogen reserves, and few mitochondria are characteristics of A) slow fibers. B) intermediate fibers. C) fast fibers. D) red muscles. E) fatty muscles. Answer: C Learning Outcome: 10-7 Bloom's Taxonomy: Knowledge

109) Which of the following types of muscle fibers are best adapted for prolonged contraction such as standing all day? A) uninucleated fibers B) striated fibers C) fast fibers D) slow fibers E) intermediate fibers Answer: D Learning Outcome: 10-7 Bloom's Taxonomy: Comprehension

110) Muscular force can be adjusted to match different loads by A) varying the frequency of action potentials in motor neurons. B) recruiting larger motor units. C) recruiting more motor units. D) involving more muscle fibers in the contraction. E) All of the answers are correct. Answer: E Learning Outcome: 10-7 Bloom's Taxonomy: Comprehension

29 Copyright © 2015 Pearson Education, Inc. 111) Which of the following statements is false? A) Cardiac muscle contractions cannot be summated. B) Skeletal muscle contractions may be summated. C) Skeletal muscle and cardiac muscle stimulation is neural. D) Cardiac muscle has a striated appearance. E) Cardiocytes are interconnected through intercalated discs. Answer: C Learning Outcome: 10-8 Bloom's Taxonomy: Knowledge

112) The ability of smooth muscle to function over a wide range of lengths is called A) elasticity. B) contractility. C) extensibility. D) plasticity. E) variability. Answer: D Learning Outcome: 10-8 Bloom's Taxonomy: Knowledge

113) Which of the following is not characteristic of smooth muscle? A) The striations are due to the orderly arrangement of actin and myosin. B) Neurons that innervate smooth muscles are under involuntary control. C) Smooth muscle cells are uninucleate. D) Smooth muscles do not contain sarcomeres. E) The thin filaments of smooth muscle fibers are attached to dense bodies. Answer: A Learning Outcome: 10-8 Bloom's Taxonomy: Knowledge

114) Which of the following is not a function of smooth muscle tissue? A) altering the diameter of the respiratory passageways B) elevating hairs on the arm C) forcing blood from the heart into the major arteries D) moving food materials along the digestive tract E) forcing urine out of the urinary tract Answer: C Learning Outcome: 10-8 Bloom's Taxonomy: Knowledge

1) A(n) ______can be described as a broad tendinous sheet. A) fasciae B) retinaculum C) aponeurosis D) interstitium E) tympanum Answer: C Learning Outcome: 10-2 Bloom's Taxonomy: Knowledge

2) The protein that is found in the Z line of a sarcomere is called A) actinin. B) titin. C) nebulin. D) myosin. E) actin. Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

3) The protein that regulates muscle contraction by controlling the availability of active sites on actin is called A) actin. B) titin. C) myosin. D) tropomyosin. E) nebulin. Answer: D Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

4) Thin filaments are mostly made of the protein A) actin. B) titin. C) myosin. D) tropomyosin. E) nebulin. Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

31 Copyright © 2015 Pearson Education, Inc. 5) Thick filaments are made of the protein A) actin. B) titin. C) myosin. D) tropomyosin. E) nebulin. Answer: C Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

6) Stem cells located between the endomysium and sarcolemma that function in the repair of damaged muscle tissue are called A) myocytes. B) satellite cells. C) endocytes. D) sarcocytes. E) creatinocytes. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

7) The complex of a transverse tubule and two adjacent terminal cisternae is known as a A) trimer. B) triad. C) triptych. D) trisome. E) trilogy. Answer: B Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

8) The structural theory that explains how a muscle fiber contracts is called the ______theory. A) sliding filament B) excitation-contraction coupling C) neuromuscular D) muscle contraction E) action-myosin interaction Answer: A Learning Outcome: 10-3 Bloom's Taxonomy: Knowledge

32 Copyright © 2015 Pearson Education, Inc. 9) Communication between axons and muscle fibers occurs at specialized synapses called A) nervous units. B) synaptic terminals. C) motor end plates. D) motor units. E) neuromuscular junctions. Answer: E Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

10) Active sites become exposed when calcium ions bind to A) tropomyosin. B) actin. C) myosin. D) troponin. E) calcium channels. Answer: D Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

11) Cross bridge detachment is caused by ______binding to the myosin head. A) ATP B) calcium C) magnesium D) acetylcholine E) acetylcholinesterase Answer: A Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

12) The sequence of processes that links the action potential to contraction is called A) neuromuscular junction. B) action potential propagation. C) excitation-contraction coupling. D) cross bridge formation. E) sliding filament theory. Answer: C Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

33 Copyright © 2015 Pearson Education, Inc. 13) An infection by the bacterium Clostridium tetani can cause the disease called A) cholera. B) polio. C) botulism. D) tetanus. E) muscular dystrophy. Answer: D Learning Outcome: 10-4 Bloom's Taxonomy: Knowledge

14) A single contraction-relaxation cycle in a muscle fiber produces a(n) A) cramp. B) twitch. C) tetanic contraction. D) action potential. E) motor unit. Answer: B Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

15) A muscle produces its highest tension when in complete A) recovery. B) treppe. C) wave summation. D) aerobic metabolism. E) tetanus. Answer: E Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

16) Identify the incorrect statement about a single motor unit. A) The more neurons involved, the more powerful the contraction. B) The smaller the number of muscle fibers, the more precise the movement. C) Fine motor skills depend on the development of small motor units. D) Some motor units include as many as 2000 muscle fibers. E) Muscle fibers of one motor unit intermingle with the fibers of another motor unit. Answer: A Learning Outcome: 10-5 Bloom's Taxonomy: Comprehension

1) Describe the basic sequence of events that occurs as an action potential arrives at the neuromuscular junction and is transmitted to the muscle cell. Answer: The action potential triggers the exocytosis of neurotransmitters stored in vesicles in the axon terminal. This acetylcholine binds to receptors in the motor end plate, increasing the muscle membrane permeability to sodium. Acetylcholinesterase destroys the acetylcholine, ensuring that each nerve action potential produces only a single twitch. The influx of these positive sodium ions triggers an action potential. The action potential spreads in both directions away from the motor end plate across the entire surface of the muscle fiber and into the interior via transverse tubules, triggering a pulse of calcium ion release from the sarcoplasmic reticulum, which generates a brief small twitch. With additional stimuli, calcium ion builds up and higher tensions are produced. Learning Outcome: 10-4 Bloom's Taxonomy: Comprehension

2) A hypothetical genetic disease causes the body to produce antibodies that compete with acetylcholine for receptors on the motor end plate. Patients with this disease exhibit varying degrees of muscle weakness in the affected muscles. If you could administer a drug that inhibits acetylcholinesterase or a drug that blocks acetylcholine, which one would you use to alleviate these symptoms? Answer: This is a case of competition between acetylcholine and the antibody. To make the patient's acetylcholine more effective, a drug that inhibits acetylcholinesterase would slow the breakdown of acetylcholine, relieving some of the weakness. An acetylcholine blocker would be worse than doing nothing. Learning Outcome: 10-4 Bloom's Taxonomy: Application

3) Describe a motor unit. How many fibers does a motor unit contain? Answer: A motor unit consists of all of the skeletal muscle fibers controlled by a single motor neuron. They may have as few as 10 fibers (eye muscles) or as many as 10,000 (back muscles). Learning Outcome: 10-5 Bloom's Taxonomy: Knowledge

4) Thirty minutes after Mary has completed a 25-km race, she begins to notice severe muscle soreness and stiffness in her legs. Her urine is dark colored. She wonders whether she may have damaged her muscles during the race. She visits the ER, and the doctor orders several blood tests. What kind of blood tests can help determine whether muscle damage has occurred? Answer: If muscle damage occurred, the doctor would find enzymes such as creatine kinase and proteins such as myoglobin or troponin in the bloodstream released by injured skeletal muscle cells. The level of these substances correlates with the severity of the injury. Learning Outcome: 10-6 Bloom's Taxonomy: Application

35 Copyright © 2015 Pearson Education, Inc. 5) Megan wants to enter a weight-lifting competition and consults you as to what type of muscle fibers she needs to develop and how she should go about it. What would you suggest to her? Answer: Weight lifting requires anaerobic endurance. Megan would want to develop her fast fibers for short-term maximum strength. She would achieve this by engaging in activities that involve frequent, brief, but intensive workouts, such as with heavy weights to the point of muscle fatigue. The fatigue triggers the production of new myofilament proteins, leading to muscle bulk and strength. Learning Outcome: 10-7 Bloom's Taxonomy: Application

6) Many visceral smooth muscle cells lack motor neuron innervation. How are their contractions coordinated and controlled? Answer: Gap junctions interconnect visceral smooth muscle fibers. An action potential that begins in one will spread to its surrounding neighbors. The action potential can be triggered by stretching, hormones, chemical changes, or stimulation at a myoneural junction on a distant smooth muscle cell. Learning Outcome: 10-9 Bloom's Taxonomy: Comprehension