Muscular System Chapter 7 Movement Unit

2 Fig. 7.1 Review:

3 Functions of Skeletal Muscle:  Support the body (opposes the force of gravity)  Make bones and other body parts move  Maintain a constant body temperature  Assist movement in cardiovascular and lymphatic vessels  Protect internal organs and stabilize joints

4 Microscopic Anatomy of Skeletal Muscle:  What do we already know from histology? Striations.  Arrangement of myofilaments in a muscle fiber (cell).  Normal cell with some specialized terms for cell parts. (Plasma membrane = sarcolema, endoplasmic reticulum = sarcoplasmic reticulum)

5 Microscopic Anatomy of Muscle (Sarcoplasmic Reticulum)  Remember this is the ER for muscle cells.  Sarcoplasmic reticulum has specialized pockets to store calcium ions (Ca 2+ ) which is essential for muscle contraction.  The sarcoplasmic reticulum encases hundreds of myofibrils which allow for contraction of the muscle cell.

6 Microscopic Anatomy of Muscle:  Myofibrils run the length of the muscle fiber.  Striations are formed by the placement of these myofibrils forming sarcomeres.  Sarcomeres contain two types of protein fibers: actin (thin and intertwined) and myosin (thick and shaped like golf club).

7 Fig. 7.3a

8 Fig. 7.3b

9 Microscopic Anatomy of Muscle:  Sliding Filaments – when the muscles are triggered by motor nerve cells, impulses travel down the T-tubule of the sarcomere (see previous picture). Calcium is then released from the sarcoplasmic reticulum. This causes the sarcomere to shorten. The actin slides across the myosin. ATP provides the power for this contraction.

10 Fig. 7.4

11 Fig. 7.5

12 Macroscopic Anatomy of Muscle:  3 Layers of connective tissue are part of each muscle: Epimysium – surrounds entire muscle, dense layer of collagen fibers. Perimysium – divides muscle into compartments called fascicles. Endomysium – delicate connective tissue that surrounds each muscle cell or fiber.  Where these connective tissues run together at the end of muscles they form tendons or aponeurosis.

13 Fig. 7.2a

14 Fig. 7.5a

15 Fig. 7.5b

16 Fig. 7.6

17 Fig. 7.7

18 Fig. 7.8

19 Fig. 7.8a

20 Fig. 7.8b

21 Fig. 7.8c

22 Fig. 7.9

23 Fig. 7.10

24 Fig. 7.10a

25 Fig. 7.10b

26 Fig. 7.11

27 Fig. 7.12

28 Fig. 7.13

29 Fig. 7.14

30 Fig. 7.15

31 Fig. 7.16a

32 Fig. 7.16ab

33 Fig. 7.16b

34 Fig. 7.16c

35 Fig. 7.16cd

36 Fig. 7.16d

37 Fig. 7.17

38 Fig. 7.18

39 Fig. 7.19

40 Fig. 7.20

41 TA p120a

42 TA p120b

43 TA p120c

44 Fig. 7.1

45 Fig. 7.2

46 Fig. 7.2a

47 Fig. 7.2b

48 Fig. 7.2c

49 Fig. 7.3a

50 Fig. 7.3b

51 Fig. 7.4

52 Fig. 7.5

53 Fig. 7.5a

54 Fig. 7.5b

55 Fig. 7.6

56 Fig. 7.7

57 Fig. 7.8

58 Fig. 7.8a

59 Fig. 7.8b

60 Fig. 7.8c

61 Fig. 7.9

62 Fig. 7.10

63 Fig. 7.10a

64 Fig. 7.10b

65 Fig. 7.11

66 Fig. 7.12

67 Fig. 7.13

68 Fig. 7.14

69 Fig. 7.15

70 Fig. 7.16a

71 Fig. 7.16ab

72 Fig. 7.16b

73 Fig. 7.16c

74 Fig. 7.16cd

75 Fig. 7.16d

76 Fig. 7.17

77 Fig. 7.18

78 Fig. 7.19

79 Fig. 7.20

80 TA p120a

81 TA p120b

82 TA p120c

83 Table 7.1

84 Table 7.2

85 Table 7.3

86 Table 7.4

87 Table 7.5

88 Table 7A