the muscular system - cengage...

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C H A P T E R 9

ACTIVITIES

A. CompletionFill in the blank spaces with the correct term.

1. Skeletal muscle is striated and .

2. Because their length is greater than their width, skeletal muscle cells are referred to as muscle .

3. The sarcolemma is surrounded by three types of connective tissue; they are the , the , and the .

4. A bands are the bands and I bands are the bands.

5. There are no cross-bridges in the .

6. The actual process of contraction occurs in the area called the .

7. Muscle fibrils are surrounded by membranes in the form of and .

O B J EC T I V ES

After studying this chapter, you should be able to:

1. Describe the gross and microscopic anatomy of skeletal muscle.

2. Describe and compare the basic differences between the anatomy of skeletal, smooth, and cardiac muscle.

3. Explain the current concept of muscle contraction based on three factors: neuroelectrical, chemical, and energy sources.

4. Define muscle tone and compare isotonic and isometric contractions.

5. List factors that can cause muscles to malfunction, causing various disorders.

6. Name and identify the location of major superficial muscles of the body.

The Muscular System

NAME: DATE:

38736_09_Ch09_p133-148.indd 13338736_09_Ch09_p133-148.indd 133 8/26/09 12:06:26 PM8/26/09 12:06:26 PM

134 Section 2 • Chapter Exercises


8. These structures are referred to as the system.

9. An irregular curtain around each of the fibrils is the .

10. A motor unit is innervated by a(n) .

11. Each motor unit in the muscle contains about 10 muscle cells.

12. A muscle fiber’s membrane is surrounded by .

13. The two minerals causing a resting potential in a muscle are and .

14. The electrical potential is caused by a rapid influx of ions.

15. A muscle cell generating its own impulse is called its .

16. The two inhibitor substances surrounding the actin are and .

17. The substance negating their effect is .

18. The discoverer of the protein myosin was .

19. During contraction, the width of the A bands remains constant while the move closer.

20. The four sources of ATP for the energy of contraction are , , , and plus two ATP.

21. The all-or-none law states that a muscle contraction either or it .

22. A constant state of partial contraction is called .

23. The muscle that is nonstriated and found in hollow structures is .

24. Smooth muscle contraction occurs without the regular rearrangement of .

25. Cardiac muscle is under the control of the nervous system.

26. Fibrillation of cardiac muscle can result in .

27. Prime movers are .

28. assist the prime movers.

29. Muscles found directly under the skin are muscles.

30. is muscle pain.

31. Doctors of medicine take a therapeutic approach to medicine by placing greater emphasis on the relationship between the organs and the musculoskeletal system.

32. is a form of rheumatism but does not affect the joints.

33. Stepping on an old nail can transfer the bacterium causing to body tissues.

B. MatchingMatch the term on the right with the definition on the left.

34. striated muscle a. resting potential

35. electrical cell membrane b. phosphocreatine

36. delicate connective tissue c. trapezius

37. individual bundles of cells d. myosin

38. surrounds whole muscle e. isotonic contraction

39. dark bands of protein f. origin

40. light of protein g. fi brillation

41. forms irregular curtain h. insertion


Chapter 9 • The Muscular System 135


42. inside minus outside plus i. skeletal

43. muscle impulse j. fascicle

44. contain ATP molecule k. action potential

45. only in muscle tissue l. sarcolemma

46. tension remains the same m. actin

47. rapid uncontrolled contraction n. zygomaticus

48. fi xed attachment of muscle o. sarcoplasmic reticulum

49. movable attachment of muscle p. myosin fi laments

50. prime mover q. endomysium

51. draw scalp backward r. epimysium

52. smiling muscle s. agonists

53. between the neck and clavicle t. occipitalis

C. Key TermsUse the text to look up the following terms. Write the definition or explanation.

54. Action potential:

55. All-or-none law:

56. Antagonists:

57. Bands:

58. Contracture:

59. Cramps:




60. Electrical potential:

61. Fascicle:

62. Fibrillation:

63. H band:

64. Hypertrophy:

65. I band:

66. Insertion:

67. Isometric activity:

68. Isotonic activity:

69. Motor unit:




70. Muscle twitch:

71. Myalgia:

72. Perimysium:

73. Phosphocreatine:

74. Plantar fasciitis:

75. Polio:

76. Psoas:

77. Rigor mortis:

78. Sarcotubular system:

79. Synergists:

80. T system:




D. Labeling Exercise 81. Label the superficial muscles as indicated in Figure 9-1.

Frontalis E.

Orbicularis oculi

Masseter

F.

G.

Rectus abdominis

Linea alba

Extensors of hand

Tensor fasciae latae

Adductors of thigh

Rectus femoris

Vastus medialis

I.

Soleus

Tibia

H.

A.

B.

C.

Serratus anterior

External oblique

Flexors of handand fingers

Sartorius

D.

Patella

Patellar ligament

Tibialis anterior

Peroneus longus

Figure 9-1




A.

B.

C.

D.

E.

F.

G.

H.

I.




A.

Occipitalis

Sternocleidomastoid

D.

Infraspinatus

Rhomboid major

Extensors of the hand and fingers

Iliotibial tract

Biceps femoris

Semitendinosus

Semimembranosus

E.

Soleus

Achille’s tendon

Seventh cervical vertebra

Teres minor

Teres major

Triceps brachii

B.

C.

Adductor magnus

Gracilis

Gastrocnemius

Peroneus longus

Peroneus brevis

Hamstrings

82. Label the superficial muscles as indicated in Figure 9-2.

Figure 9-2




A. D.

B. E.

C.

E. Coloring Exercise 83. Using Figure 9-3, color the gluteus maximus red, the biceps femoris (long head) blue, the biceps femoris

(short head) yellow, the soleus green, and the calcaneal tendon orange.

Figure 9-3




F. Critical ThinkingAnswer the following questions in complete sentences.

84. Why should weightlifters do aerobic exercises for maximal physical fitness?

85. Explain two ways in which prolonged exertion during hot weather might cause muscles to malfunction.

86. Why does stimulation of nerves with electrical current help stave off muscle atrophy for a short period of time?

87. Explain the function of troponin and tropomyosin and what negates them.

88. On what does the strength of contractions depend? Explain.

89. Identify age-related changes in the muscle system. Explain what a sports medicine physician and a massage therapist can do to help.




G. Crossword Puzzle

1 2

3 4 5

6 7 8

9 10

11

12

13

14

15

16

17 18 19

20

21 22

23

24

25

26

27

28

29

30

Complete the crossword puzzle using the following clues.

ACROSS DOWN

3. Muscle found in hollow body structures 1. Injection site in the arm

7. Contraction when lifting a weight 2. Muscle inflammation

9. Skeletal muscle type 4. Thick protein filament in muscle cells

13. Muscle that closes the jaw 5. Constant state of partial contraction

14. Muscle pain 6. Inhibitor substance

15. Movable muscle attachment 8. Area between Z lines

16. Muscle that protrudes the lower lip 10. Muscle between the neck and clavicle

18. Electrically polarized cell membrane 11. Skeletal muscle bundles

25. Fixed muscle attachment 12. Muscle that raises the mandible

26. Muscle that moves the head 17. Muscles that assist the prime mover

28. Activity from tension against muscles 19. Neurotransmitter substance




29. Muscle that compresses the cheek 20. Rapid source of high-energy ATP

30. Thin filaments of protein 21. Increase in muscle size

22. Actin united with myosin

23. Smiling and laughing muscles

24. Rapid, uncontrolled contraction of heart cells

27. Prime mover

Nadea, a 35-year-old woman, tells the nurse practitioner at the local clinic that she is having problems holding her eyes open, smiling, and keeping her lips closed. She also states that she feels generally weak and easily fatigued. The nurse notes that Nadea has droopy eyelids and her face has little expression.

QUESTIONS

1. What condition might be causing Nadea’s symptoms of muscle fatigue and weakness?

2. What muscles does this disorder affect fi rst?

3. Why does this condition develop?

C A S E S T U D Y

CHAPTER QUIZ

1. Muscles make up what percentage of body weight?

a. 10–20% d. 40–50% b. 20–30% e. 50–60% c. 30–40%

Answer:

2. The longest and most slender muscle fi bers are

a. smooth d. uninucleated b. skeletal e. none of the above c. cardiac

Answer:




3. The entire muscle consists of a number of skeletal muscle bundles called

a. perimysium d. actin b. myosin e. none of the above c. fasciculi

Answer:

4. The sarcomere is the area between two

a. Z bands d. A bands b. H bands e. none of the above c. I bands

Answer:

5. The layer of areolar tissue covering the whole muscle trunk is called

a. fascicle d. fascia b. fasciculi e. none of the above c. epimysium

Answer:

6. The light bands are the

a. A bands d. I bands b. Z lines e. none of the above c. H bands

Answer:

7. The sarcotubular system is made up of the sarcoplasmic reticulum and the

a. T system d. vesicle system b. H system e. none of the above c. sarcomere

Answer:

8. On the average, a single motor nerve fi ber innervates about how many muscle cells?

a. 100 d. 250 b. 150 e. none of the above c. 200

Answer:

9. Which of the following properties do muscle cells NOT possess?

a. excitability d. elasticity b. conductivity e. none of the above c. contractility

Answer:

10. Which of the following is a neurotransmitter?

a. acetylcholine d. tropomyosin b. myosin e. none of the above c. actin

Answer:




11. Muscle contraction is

a. resting potential d. chemical potential b. electrical potential e. none of the above c. action potential

Answer:

12. Calcium negates the effect of

a. myosin d. sodium b. troponin e. none of the above c. actin

Answer:

13. The sodium–potassium pump restores

a. resting potential d. chemical potential b. electrical potential e. none of the above c. action potential

Answer:

14. Actin was discovered in

a. 1868 d. 1960 b. 1934 e. none of the above c. 1942

Answer:

15. Which of the following retains the same width during contraction?

a. A bands d. Z lines b. I bands e. none of the above c. H bands

Answer:

16. Which of the following moves apart at the end of a contraction?

a. A bands d. Z lines b. I bands e. none of the above c. H bands

Answer:

17. ATP is synthesized by all of the following EXCEPT

a. glycolysis d. breakdown of phosphocreatine b. Krebs citric acid cycle e. none of the above c. electron transport

Answer:

18. Which of the following is a rapid source of high-energy ATP for muscle contraction?

a. glycolysis d. breakdown of phosphocreatine b. Krebs citric acid cycle e. none of the above c. electron transport

Answer:




19. Which of the following does a contraction NOT depend on?

a. strength of stimulus d. temperature b. duration of stimulus e. none of the above c. speed of stimulus

Answer:

20. Muscle remains at constant length but tension increases. What type of contraction is this?

a. isotonic d. internal b. isometric e. none of the above c. tonal

Answer:

21. Muscle shortens and thickens while tension remains constant. What type of contraction is this?

a. isotonic d. internal b. isometric e. none of the above c. tonal

Answer:

22. Some muscles will always be contracting while others are at rest. What type of contraction is this?

a. isotonic d. external b. isometric e. none of the above c. tonal

Answer:

23. Two of the three kinds of muscle in the body are uninucleated; they are

a. smooth and cardiac d. visceral and striated b. smooth and skeletal e. none of the above c. cardiac and skeletal

Answer:

24. Contraction is fastest in which kind of muscle?

a. smooth d. visceral b. cardiac e. none of the above c. skeletal

Answer:

25. The wide, fl at attachment of muscle to bone is called

a. ligament d. aponeurosis b. tendon e. origin c. insertion

Answer:

26. The attachment of the biceps to the forearm is the

a. agonist d. ligament b. insertion e. none of above c. origin

Answer:




27. Muscles that straighten a joint are called

a. agonists d. antagonists b. synergists e. origins c. insertions

Answer:

28. An increase in muscle size is called

a. atrophy d. myalgia b. myositis e. myasthenia gravis c. hypertrophy

Answer:

29. Muscle weakness is called


Answer:

30. Infl ammation of muscle tissue is called


Answer:

31. In the 1940s and 1950s many children developed paralysis of their limbs and had to be placed in “iron lungs” after contracting

a. myalgia d. myositis b. plantar fasciitis e. polio c. tetanus

Answer:

32. Which of the following muscles extends the thigh?

a. adductor magnus d. adductor longus b. abductor brevis e. sartorius c. tensor fascia lata

Answer:

33. The main muscles that close the jaw are the temporalis and the

a. superior rectus d. buccinator b. masseter e. orbicularis oris c. pterygoid

Answer:


the muscular system - cengage...

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