1. Essentials of Anatomy and Physiology Fifth edition Seeley, Stephens and Tate Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 6: Skeletal System, Bones and Joints

2. The Skeletal System Slide 5.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Components of the skeletal system  Bones (skeleton)  Joints  Cartilages  Ligaments

3. The Skeletal System Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Two subdivisions  Axial skeleton  Appendicular skeleton

4. Functions of Bones Slide 5.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Support of the body  Protection of soft organs  Movement due to attached skeletal muscles: “passive”  Storage of minerals and fats  Blood cell formation

5. Bones of the Human Body Slide 5.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The skeleton has ~206 bones  Two basic types of bone tissue  Compact bone  Dense  Spongy bone  Small needle-like pieces of bone  Many open spaces Figure 5.2b

6. Classification of Bones Slide 5.4a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Long bones  Typically longer than wide  Have a shaft with heads at both ends  Contain mostly compact bone Examples: Femur, humerus

7. Classification of Bones Slide 5.4b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Short bones  Generally cube-shape  Contain mostly spongy bone  Examples: Carpals, tarsals

8. Classification of Bones on the Basis of Shape Slide 5.4c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.1

9. Classification of Bones Slide 5.5a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Flat bones  Thin and flattened  Usually curved  Thin layers of compact bone around a layer of spongy bone  Examples: Skull, ribs, sternum

10. Classification of Bones Slide 5.5b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Irregular bones  Irregular shape  Do not fit into other bone classification categories  Example: Vertebrae and hip

11. Classification of Bones on the Basis of Shape Slide 5.5c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.1

12. Gross Anatomy of a Long Bone Slide 5.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Diaphysis  Shaft  Made of compact bone  Epiphysis  Expanded ends of long bones  Covered with dense bone  Internal structure is spongy bone Figure 5.2a

13. Structures of a Long Bone Slide 5.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Periosteum  Outside covering of the diaphysis  Fibrous connective tissue membrane  Arteries  Supply bone cells with nutrients Figure 5.2c

14. Structures of a Long Bone Slide 5.8a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Articular cartilage  Covers surface of epiphyses  Hyaline cartilage  Decreases friction at joint surfaces Figure 5.2a

15. Structures of a Long Bone Slide 5.8b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Medullary cavity  Cavity in shaft  Contains yellow marrow in adults  Contains red marrow in infants Figure 5.2a

16. Microscopic Anatomy of Bone Slide 5.10a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Osteon (Haversian System)  A subunit of compact bone  Central (Haversian) canal  Opening in the center of an osteon  Carries blood vessels and nerves

17. Microscopic Anatomy of Bone Slide 5.10b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.3

18. Microscopic Anatomy of Bone Slide 5.11a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lacuna(e)  Cavities containing osteocytes  Arranged in concentric rings  Lamella(e)  Rings of compact bone  Lacunae lie between rings Figure 5.3

19. Microscopic Anatomy of Bone Slide 5.11b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Canaliculi (-us)  Tiny canals  Radiate from the central canal to lacunae  Form a transport system Figure 5.3

20. Types of Bone Cells Slide 5.15 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Osteocytes  Mature bone cells (bone maintenance)  Osteoblasts  Bone-forming cells  Osteoclasts  Bone-destroying cells  Break down bone matrix for remodeling and release of calcium

21. Bone Growth: Endochondral Slide 5.13a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 1) A cartilage model is produced by chondrocytes It is surrounded by perichondrium, a membrane 2) A bone “collar” is produced by osteocytes The perichondrium of the diaphysis is now termed periosteum

22. Long Bone Formation and Growth Slide 5.14a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.4a

23. Bone Growth: Endochondral Slide 5.13a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 3) Chondrocytes hypertrophy (enlarge) and cartilage is calcified 4) A primary ossification center forms  Blood vessels and osteoblasts invade the calcified cartilage  Osteoblasts lay down bone matrix  Trabeculae are formed

24. Long Bone Formation and Growth Slide 5.14a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.4a

25. Bone Growth: Endochondral Slide 5.13a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 5) Around the time of birth, secondary ossification centers form in the epiphyses  Bone formation is incomplete at birth  The skeleton is not complete until the late teens (females) or early twenties (males)

26. Long Bone Formation and Growth Slide 5.14a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.4a

27. Bone Growth: Endochondral Slide 5.13a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Epiphyseal plates allow for growth of long bone during childhood  New cartilage is continuously formed  Older cartilage becomes ossified  Cartilage is broken down  Bone replaces cartilage

28. Long Bone Formation and Growth Slide 5.14b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.4b

29. Bone Growth: Endochondral Slide 5.13b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Bones are remodeled and lengthened until growth stops  Bones change shape (how?? DNA!!!)  Bones grow in width (osteoblasts)  Bones are remodeled by osteoclasts

30. Long Bone Formation and Growth Slide 5.14a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.4a

31. Changes in the Human Skeleton Slide 5.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  In embryos, the skeleton is primarily hyaline cartilage  During development, much of this cartilage is replaced by bone  Cartilage remains in:  Anterior portion of the nose  Parts of ribs  Joints

32. Bone Growth: Intramembranous Slide 5.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings “Between membranes” Compact Bone Spongy Bone Trabeculae Cross- section of a trabecula

33. Bone Formation: Intramembranous Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Membranous bones are incomplete at birth  Fontanelles: regions of the skull that remain as membranes  “Little fountains”  Bone formation complete by age ~2

34. Bone Fractures Slide 5.16 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  A break in a bone  Types of bone fractures  Closed (simple) fracture –does not penetrate the skin  Open (compound) fracture – broken bone penetrates through the skin  Bone fractures are treated by reduction and immobilization

35. Common Types of Fractures Slide 5.17 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 5.2

36. Repair of Bone Fractures Slide 5.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Hematoma (blood clot) is formed  Break is splinted by fibrocartilage  forms a callus (chondroblasts, other cells, and vessels)  Callus is replaced by a bone (osteoblasts)  Bony callus is remodeled (osteoclasts)

37. Repair of Bone Fractures Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Fracture Repair  Hematoma formation (A)  Callus formation (B)  Bone replacement (C )  Bone remodeling (D) A CD B

38. Bone Fractures: Osteoporosis Slide 5.16 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Most common in post-menopausal women  Also occurs in males  Due to decrease in estrogen levels  Estrogen receptors on osseous tissue affect calcium deposition  Bone becomes porous, brittle  Weight-bearing exercise, calcium supplements, estrogen will help prevent osteoporosis