2. Ch 7 Skeletal system

3. The Skeletal System Parts of the skeletal system – Bones (skeleton) – Joints – Cartilages – Ligaments Divided into two divisions – Axial skeleton- head, spine, trunk – Appendicular skeleton

4. The Axial Skeleton Figure 5.6

5. The Skull Two sets of bones – Cranium – Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint

6. Skull cavities Cranial= brain Middle & inner ear= protect delicate ear bones and nerves Nasal= allow for the warming & cleaning of air Orbital= eyeballs

7. The Skull Figure 5.7

8. Bones of the Skull Figure 5.11

9. The skull can be so thin because it has a dome shape which supports itself. Like an egg is strong Or a domed building http://www.youtube.com/watch?v=nn5s6aScc fw http://www.youtube.com/watch?v=nn5s6aScc fw http://www.youtube.com/watch?v=DiRw- PzLiXQ http://www.youtube.com/watch?v=DiRw- PzLiXQ

10. Mastoid sinus Behind ear near throat. Can become infected. Mastoiditis. Now we use antibiotics… used to have surgery!

11. mandible The largest and strongest in the skull

12. Paranasal Sinuses Hollow portions of bones surrounding the nasal cavity Functions of paranasal sinuses – Lighten the skull – Give resonance and amplification to voice Figure 5.10

13. The Hyoid Bone The only bone that does not articulate with another bone Serves as a moveable base for the tongue Figure 5.12

14. The Vertebral Column Vertebrae separated by intervertebral discs The spine has a normal curvature Each vertebrae is given a name according to its location Figure 5.14

15. Regional Characteristics of Vertebrae Figure 5.17c–d

16. Incorrectly curved spine: Kyphosis (hunch back) or Lordosis (hyper curved lumbar) or scoliosis (to the side)

17. Intervertebral disks: cushion between vertebra add flexibility & reduce shock. If a disk is injured it can become herniated. This is when part of the disk bulges out

19. Ch 6-bones

20. Crash course Skeletal system http://www.youtube.com/watch?v=RW46rQK Wa-g http://www.youtube.com/watch?v=RW46rQK Wa-g

21. Bones of the Human Body The adult skeleton has 206 bones Two basic types of bone tissue – Compact bone Homogeneous – Spongy bone Small needle-like pieces of bone Many open spaces Figure 5.2b

22. Classification of Bones on the Basis of Shape Figure 5.1

23. Classification of Bones Long bones – Typically longer than wide – Have a shaft with heads at both ends – Contain mostly compact bone Examples: Femur, humerus

24. Classification of Bones Short bones – Generally cube-shape – Contain mostly spongy bone Examples: Carpals, tarsals

25. Classification of Bones Flat bones – Thin and flattened – Usually curved – Thin layers of compact bone around a layer of spongy bone Examples: Skull, ribs, sternum

26. Classification of Bones Irregular bones – Irregular shape – Do not fit into other bone classification categories Example: Vertebrae and hip

27. Functions of Bones 1.Support of the body 2.Protection of soft organs 3.Movement due to attached skeletal muscles 4.Storage of minerals and fats 5.Blood cell formation

28. Gross Anatomy of a Long Bone Diaphysis – Shaft – Composed of compact bone Epiphysis – Ends of the bone – Composed mostly of spongy bone Figure 5.2a

29. Structures of a Long Bone Periosteum – Outside covering of the diaphysis – Fibrous connective tissue membrane Arteries – Supply bone cells with nutrients Figure 5.2c

30. Structures of a Long Bone cartilage – Covers the external surface of the epiphyses – Decreases friction at joint surfaces Figure 5.2a

31. Structures of a Long Bone Medullary cavity – Cavity of the shaft – Contains yellow marrow (mostly fat) in adults – Contains red marrow (for blood cell formation) in infants Figure 5.2a

32. Microscopic Anatomy of Bone Osteon (Haversian System) – A unit of bone Central (Haversian) canal – Opening in the center of an osteon – Carries blood vessels and nerves Perforating (Volkman’s) canal – Canal perpendicular to the central canal – Carries blood vessels and nerves

33. Microscopic Anatomy of Bone Figure 5.3

34. Microscopic Anatomy of Bone Lacunae – Cavities containing bone cells (osteocytes) – Arranged in concentric rings Lamellae – Rings of dense bone tissue around the central canal – Sites of lacunae Detail of Figure 5.3

35. Microscopic Anatomy of Bone Canaliculi – Tiny canals – Radiate from the central canal to lacunae – Form a transport system Detail of Figure 5.3

36. Types of Bone Cells Osteocytes – Mature bone cells Osteoblasts – Bone-forming cells Osteoclasts – Bone-destroying cells – Break down bone matrix for remodeling and release of calcium Bone remodeling is a process by both osteoblasts and osteoclasts: Build up and break down all of the time!

37. Bone Fractures A break in a bone Types of bone fractures – Closed (simple) fracture – break that does not penetrate the skin – Open (compound) fracture – broken bone penetrates through the skin Bone fractures are treated by reduction and immobilization – Realignment of the bone

38. Common Types of Fractures Table 5.2

39. Repair of Bone Fractures 1.Hematoma (blood-filled swelling) is formed 2.Break is splinted by fibrocartilage to form a callus 3.Fibrocartilage callus is replaced by a bony callus 4.Bony callus is remodeled to form a permanent patch

40. This area of the bone is now super strong. Because of the density the bone will not re- break here. It is scarred.

41. Stages in the Healing of a Bone Fracture Figure 5.5

42. Joints A. Functions of joints 1. Hold bones together 2. Allow for mobility B. 3 types 1.Fibrous joints a. Generally immovable (end tibia & fibula) 2. Cartilaginous joints b. Immovable or slightly moveable (vertebral column)

43. 3. Synovial joints c. Allow for movement

44. C. Synovial Joints 1. bones are separated by a joint cavity 2. Synovial fluid is found in the joint cavity a. Cracking your knuckles is pushing the fluid around in these joints Figure 5.24f–h

45. Features of Synovial Joints 3. cartilage covers the ends of bones 4.Ligaments reinforce the joint- if you have “loose” ligaments you are “double jointed”! D. Associated Structures 1.Bursae – flattened fibrous sacs filled with synovial fluid a. Not actually part of the joint, can become inflamed (bursitis)

46. The Synovial Joint Figure 5.28

47. Types of Synovial Joints Based on Shape Figure 5.29a–c

48. Figure 5.29d–f

49. VI. Types of Body Movements A. All of the joints allow for the following movements 1. Flexion 2. Extension 3. Rotation 4. Abduction 5. Adduction 6. Circumduction

50. Body Movements Figure 6.13a–c

51. Body Movements Figure 6.13d

52. 1. Special Movements a. Dorsifelxion b. Plantar flexion c. Inversion d. Eversion e. Supination f. Pronation