1. Support and Locomotion Chapter 36 1

2. Skin The body’s protection 2

3. Epidermis  the outer layer Exterior layer  25-30 layers of dead, flattened cells –Constantly being shed –Keratin  protective protein (elasticity) Interior layer  living cells continually dividing –Melanin  protective skin pigment 3

4. Epidermis cont. Epidermal ridges Fingers and palms Toes and soles Good for gripping  give increased friction 4

5. Dermis  the inner layer Blood vessels, nerves, nerve endings, hair follicles, sweat and oil glands Layer of fat underneath  insulation and protection 5

6. This picture shows a false-colored SEM of human skin. The lower portion is the living epidermis. As those cells die, they flake off and become the stratum corneum, which does most of the work creating a barrier between the body and the outside world. 6

7. Functions of the skin Regulate body temperature Sense organ Vitamin D production Physical barrier against damage and microbial invasion 7

8. Aging Drier  glands decrease production Skin loses it’s elasticity  wrinkles Accelerated by prolonged exposure to UV rays 8

9. The Skeletal System 9

10. Axial skeleton Includes the skull, vertebral column, ribs, and sternum 10

11. Appendicular skeleton Includes the bones of the arms and legs, and associated structures 11

12. Joints Places where bones are connected 12

13. Ball-and-socket joint Allows for rotational movement Hips and shoulders 13

14. Hinge joint Allows for back-and- forth movement Elbows, knees, fingers, and toes 14

15. Pivot joint Allows bones to twist around each other Neck and elbows 15

16. Gliding joint Allows bones to slide past each other Wrists and ankles 16

17. Fixed joint Also called a fused joint Allows for no motion Skull 17

18. Cartilage Bones are cushioned by a thin layer of cartilage Flexible, elastic tissue Nose, ears, trachea, between each vertebrae 18

19. Bursae Fluid-filled sacs between bones Absorb shock 19

20. Arthritis Inflammation of the joints Wearing down of cartilage Bone spurs  splinters Causes  infections, aging, injury, genetic 20

21. Connective tissue Ligaments  connect bone to bone –Sprain  torn or stretched ligament Tendons  connect muscles to bones –Tendonitis  inflammation of the tendon 21

22. Bone Structure 22

23. Compact bone Very dense and strong Outside of ends and along shafts Osteocytes  bone cells 23

24. Osteon systems (Haversian canals) –Openings which allow blood vessels and nerves through bone 24

25. Spongy bone Less dense, porous Ends of bones 25

26. Periosteum Outer covering of bone shafts 26

27. Osteoblasts  potential bone cells Secrete a protein called collagen Deposition of minerals turns them into osteocytes  ossification 27

28. Osteoporosis  loss of bone mass Growth –Length: cartilage plates at ends –Width: outer surface After growth  repair and maintenance 28

29. Marrow  found at the center of bones Red marrow Long bones only –Production of blood cells Yellow marrow Most bones –Stored fat 29

30. Functions of the skeletal system Protects internal organs Framework for body tissues Attachment for muscles Production of blood cells Mineral storage 30

31. Skeletal system 31

32. Muscles 3 types 32

33. Smooth muscle Sheets of cells Walls of internal organs and blood vessels Function  squeezing (pressure) Involuntary  not under conscious control 33

34. Smooth muscle tissue 34

35. Cardiac muscle Found in your heart Interconnected bands of muscle fibers  striated Adapted to generate and conduct electrical impulses Involuntary 35

36. Cardiac muscle tissue 36

37. Skeletal muscle Attached to bones Controls movement Work in opposing pairs  1 bends a limb and the other extends the limb Striated in appearance Voluntary 37

38. Skeletal muscle tissue 38

39. Muscle and nerves 39

40. Skeletal muscle contraction 40

41. Muscle strength The number of muscle fibers you have is fixed before birth Muscle fibers get bigger and more fibers contract as you increase your strength 41

42. Muscle fatigue  when muscles hurt after use Due to decreased available oxygen Cells switch from aerobic to anaerobic Lactic acid buildup  toxic, causes pain Cure  rest Not resting can result in permanent muscle damage 42

43. Comparative anatomy 43

44. Amoeba Pseudopods  “false feet” Extensions of the cell membrane that can reach in any direction Locomotion 44

45. Amoeba with pseudopods 45

46. Paramecium Have cilia to propel them through the water Locomotion 46

47. Paramecium with cilia 47

48. Hydra Pull with tentacles Glide on base Somersaulting Movement 48

49. Hydra with tentacles 49

50. Earthworm Setae  bristles used as anchors Longitudinal muscles  shorten body Circular muscles  lengthen body 50

51. 51

52. Grasshopper Jointed appendages Walking legs and jumping legs 2 sets of wings Exoskeleton made of chitin –Attachment site for muscles 52

53. 53