Topic 6 - Muscle

12. Which of the following statements is false? a. Slow fibers have a small network of capillaries. b. Slow fibers contain the pigment myoglobin. c. Slow fibers contain a large number of mitochondria. d. Slow fibers contract for extended periods.

A

14. Smooth muscles differ from skeletal and cardiac muscles in that they ________. a. lack myofibrils b. are under voluntary control c. lack myosin d. lack actin

A

15. Which of the following statements describes smooth muscle cells? a. They are resistant to fatigue. b. They have a rapid onset of contractions. c. They cannot exhibit tetanus. d. They primarily use anaerobic metabolism.

A

20. Smooth muscle is *a. involuntary and nonstriated. b. responsible for movement of the skeleton. c. involved in contraction of the heart. d. connected to bones by tendons. e. both involuntary and nonstriated, and is also involved in contraction of the heart.

A

8. A sprinter would experience muscle fatigue sooner than a marathon runner due to ________. a. anaerobic metabolism in the muscles of the sprinter b. anaerobic metabolism in the muscles of the marathon runner c. aerobic metabolism in the muscles of the sprinter d. glycolysis in the muscles of the marathon runner

A

9. The muscles of a professional sprinter are most likely to have ________. a. 80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers b. 20 percent fast-twitch muscle fibers and 80 percent slow-twitch muscle fibers c. 50 percent fast-twitch muscle fibers and 50 percent slow-twitch muscle fibers d. 40 percent fast-twitch muscle fibers and 60 percent slow-twitch muscle fibers

A

10. The muscles of a professional marathon runner are most likely to have ________. a. 80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers b. 20 percent fast-twitch muscle fibers and 80 percent slow-twitch muscle fibers c. 50 percent fast-twitch muscle fibers and 50 percent slow-twitch muscle fibers d. 40 percent fast-twitch muscle fibers and 60 percent slow-twitch muscle fibers

B

16. Which of the following statements is correct about what happens during flexion? a. The angle between bones is increased. b. The angle between bones is decreased. c. The bone moves away from the body. d. The bone moves toward the center of the body.

B

18. Which muscle extends the forearm? a. biceps brachii b. triceps brachii c. brachialis d. deltoid

B

2. The correct order for the smallest to the largest unit of organization in muscle tissue is ________. a. fascicle, filament, muscle fiber, myofibril b. filament, myofibril, muscle fiber, fascicle c. muscle fiber, fascicle, filament, myofibril d. myofibril, muscle fiber, filament, fascicle

B

4. The cell membrane of a muscle fiber is called ________. a. myofibril b. sarcolemma c. sarcoplasm d. myofilament

B

6. During muscle contraction, the cross-bridge detaches when ________. a. the myosin head binds to an ADP molecule b. the myosin head binds to an ATP molecule c. calcium ions bind to troponin d. calcium ions bind to actin

B

57. What is found within the intercalated disks of cardiac muscle? a. sarcoplasmic reticulum b. gap junctions c. dense connective tissue d. bone e. myoglobin 58. Which of the following is not a function of skeletal muscles? a. pumping of blood throughout the body b. support c. movement of bones d. maintenance of body temperature e. protection of internal organs

B, A

59. What structure attaches a muscle to a bone? a. ligaments b. tendons c. bursae d. sarcolemma e. sarcoplasm 60. What muscle works in a pair with the biceps brachii? a. the triceps brachii b. the trapezius c. the masseter d. the pectoralis major e. the sartorius

B, A

21. The ability to extend a leg is the result of a. contraction of ligaments and tendons. b. contraction of a muscle. c. lengthening of a muscle. d. a combination of push and pull by antagonistic muscle pairs. e. relaxation of myosin and actin proteins. 22. Each muscle fiber is also called a a. muscle. b. muscle cell. c. myofibril. d. sarcomere. e. all of these

B, B

39. White muscles are designed to contract a. quickly. b. quickly and for short periods. c. slowly. d. slowly for short periods. e. slowly for long periods. 40. The basic unit of contraction in a muscle is the a. myofibril. b. sarcomere. c. sliding filament. d. contractile vacuole. e. Z band.

B, B

67. In good muscle tone, how many motor units are contracted? a. none b. some c. all d. 5 -10% of the motor units e. 10 - 15% of the motor units 68. What is the reservoir for Ca2+ in the body? a. muscles b. bones c. liver d. brain e. blood

B, B

29. Which of the following statements is true of the all-or-none principle? a. It explains muscle fatigue. b. It describes the contraction of individual muscle cells. c. A muscle, such as the biceps, either contracts or it doesn't. d. Muscle tone is the direct result of this phenomenon. e. It is equivalent to tetany. 30. Which of the following would be LEAST likely to result from aerobic exercise? a. increased number of mitochondria b. greater running endurance c. increased blood capillaries d. larger, stronger, bulging muscles e. more myoglobin

B, D

47. Repeated stimulation of a motor unit over a short period of time leads to a. fatigue. b. tetanus. c. increased muscle strength. d. muscle twitch. e. increased ATP production. 48. A steady, low-level contraction of a muscle is referred to as a. tetanus. b. treppe. c. spasm. d. tone. e. fatigue.

B, D

11. Which of the following statements is true? a. Fast fibers have a small diameter. b. Fast fibers contain loosely packed myofibrils. c. Fast fibers have large glycogen reserves. d. Fast fibers have many mitochondria.

C

19. The human biceps and triceps muscles may be described best as working a. independently. b. synergistically. c. antagonistically. d. synchronistically. e. involuntarily.

C

5. Muscle relaxation occurs when ________. a. calcium ions are actively transported into the cytoplasm b. calcium ions diffuse into the cytoplasm c. calcium ions are actively transported out of the cytoplasm d. calcium ions diffuse out of the cytoplasm

C

49. A painful muscle spasm that doesn't immediately release is a(n) a. inflammation. b. muscle tear. c. cramp. d. isotonic contraction. e. dystrophy. 50. What is the term for the sudden and involuntary contraction of a muscle? a. spasm b. twitch c. tetanus d. treppe e. paralysis

C, A

55. Of the three types of muscle tissue, which is voluntary? a. smooth muscle b. cardiac muscle c. skeletal muscle d. both smooth and skeletal e. both cardiac and skeletal 56. Of the three types of muscle tissue, which is not striated? a. smooth muscle b. cardiac muscle c. skeletal muscle d. skeletal and smooth lack striations e. cardiac and smooth lack striations

C, A

61. What is the deltoid muscle shaped like? a. a long thin line b. a square c. a triangle d. a circle e. a trapezoid 62. What is the biggest muscle (in terms of mass) in the body? a. gluteus maximus b. sartorius c. stapedius d. quadriceps femoris e. latissimus dorsi

C, A

31. Tissue-building steroids are known as a. catabolic. b. metabolic. c. anabolic. d. actinic. e. nicotinic. 32. Smooth muscle is found in a. arms and legs. b. the walls of hollow organs and tubes. c. the heart. d. the brain. e. none of these.

C, B

63. What does the word sarco mean? a. large b. short c. muscle d. tubule e. smooth 64. A muscle fiber is made up of many a. muscle cells. b. T tubules. c. myofibrils. d. fascicles. e. bursa.

C, C

65. What happens to the actin and myosin filaments when a muscle contracts? a. both of them shorten b. both of them lengthen c. both stay the same length d. actin shortens while myosin lengthens e. myosin shortens while actin lengthens 66. What supplies the energy for muscle contraction? a. actin b. myosin c. tropomyosin d. ATP e. Ca2+

C, D

37. Red muscle appears that way due to the presence of a. hemoglobin. b. iron. c. myoglobin. d. ATP. e. glucose. 38. Red muscles are designed to contract a. quickly. b. quickly and for short periods. c. slowly. d. slowly for short periods. e. slowly for long periods.

C, E

1. Muscle that has a striped appearance is described as being ________. a. elastic b. nonstriated c. excitable d. striated

D

13. Cardiac muscles differ from skeletal muscles in that they ________. a. are striated b. utilize aerobic metabolism c. contain myofibrils d. contain intercalated discs

D

17. Which of the following terms would be used in the name of a muscle that moves the leg away from the body? a. flexor b. adductor c. extensor d. abductor

D

3. According to the sliding filament model, binding sites on actin open when ________. a. creatine phosphate levels rise b. ATP levels rise c. acetylcholine levels rise d. calcium ion levels rise

D

7. Thin and thick filaments are organized into functional units called ________. a. myofibrils b. myofilaments c. T-tubules d. sarcomeres

D

23. The gastrocnemius muscle is located a. in the forelimb. b. on the back. c. in the hip area. d. in the lower leg. e. in the neck. 24. The pectoralis major muscle is located a. in the chest. b. on the back. c. near the hips. d. in the upper leg. e. in the lower leg.

D, A

33. What quality do cardiac and skeletal muscles share? a. they are both smooth muscle b. they are both voluntary muscle c. they are both involuntary muscle d. they are both striated e. they are both found in the heart 34. Smooth muscle is a. involuntary and nonstriated. b. responsible for movement of the skeleton. c. involved in contraction of the heart. d. connected to bones by tendons.

D, A

35. A strap of dense connective tissue that connects muscle to bone is (a) a. ligament. b. cartilage. c. myofibril. d. tendon. e. filament. 36. When one muscle group is stimulated, no nervous signals are sent to the opposing group. This is due to a. reciprocal innervation. b. lack of innervation. c. hyperreflexia. d. compensation. e. depolarization.

D, A

45. The neurotransmitter used for muscle contraction is a. serotonin. b. dopamine. c. GABA. d. acetylcholine. e. aspartate. 46. What contributes to muscle fatigue? a. lactic acid buildup b. glycogen depletion c. both lactic acid buildup and glycogen depletion d. loss of nerve innervation e. stretching a muscle

D, C

53. What do smooth, cardiac, and skeletal muscle all have in common? a. They are all uninucleated. b. They are all striated. c. They are all found in the walls of blood vessels. d. The cells of these muscles are all called muscle fibers. e. They all interlock at intercalated disks. 54. Of the three types of muscle tissue, which has multinucleated fibers? a. smooth muscle b. cardiac muscle c. skeletal muscle d. both smooth and skeletal muscles e. both cardiac and smooth muscles

D, C

27. A motor neuron and all the muscles under its control is called what kind of unit? a. end unit b. movement unit c. muscle unit d. motor unit e. coordination unit 28. An active, nonfatiguing muscle would be expected to have a. aerobic respiration. b. numerous mitochondria. c. moderate rates of contraction. d. aerobic respiration and moderate rates of contraction. e. aerobic respiration, numerous mitochondria, and moderate rates of contraction.

D, E

43. The element that is crucial to actual muscle contraction is a. sodium. b. potassium. c. iron. d. magnesium. e. calcium. 44. The space between the branched nerve endings and the muscle cell membrane is called a a. myelin sheath. b. synapse. c. dendrite. d. gap junction. e. tight junction.

E, B

51. Aerobic exercise affects muscle cells by a. increasing the number of mitochondria. b. increasing the size of mitochondria. c. increasing the number of capillaries supplying muscle tissue. d. increasing nourishment to the cells and waste removal from the cells. e. all of these 52. For maximum effect, one should a. perform strength training only. b. perform aerobic exercise only. c. perform both aerobic exercises and strength training. d. perform much strength training and only a little aerobic exercise. e. perform much aerobic exercise and only a little strength training.

E, C

25. Which of the following includes all the others? a. actin b. myofibril c. myosin d. myofilament e. muscle cell 26. Which of the following is NOT true of "fast" muscle in humans? a. rapid contractions b. powerful c. fewer blood capillaries d. abundant myoglobin e. fewer mitochondria

E, D

41. During muscle contractions a. the myofibrils shorten. b. the actin and myosin filaments slide over each other. c. the actin filaments move toward the middle of the sarcomere during contraction and away on relaxation. d. the muscle thickens. e. all of these. 42. When a person dies, myosin cross-bridges with actin can't break apart leading to the condition known as a. muscle spasm. b. flaccid paralysis. c. spastic paralysis. d. rigor mortis. e. habeas corpus.

E, D