1. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Human Anatomy & Physiology SEVENTH EDITION Elaine N. Marieb Katja Hoehn PowerPoint ® Lecture Slides prepared by Vince Austin, Bluegrass Technical and Community College C H A P T E R 6 Bones and Skeletal Tissues P A R T A

2. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Skeletal Cartilage  Contains no blood vessels or nerves  Surrounded by the perichondrium (dense irregular connective tissue) that resists outward expansion  Three types – hyaline, elastic, and fibrocartilage

3. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Hyaline Cartilage  Provides support, flexibility, and resilience  Is the most abundant skeletal cartilage  Is present in these cartilages:  Articular – covers the ends of long bones  Costal – connects the ribs to the sternum  Respiratory – makes up larynx, reinforces air passages  Nasal – supports the nose

4. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Elastic Cartilage  Similar to hyaline cartilage, but contains elastic fibers  Found in the external ear and the epiglottis

5. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Fibrocartilage  Highly compressed with great tensile strength  Contains collagen fibers  Found in menisci of the knee and in intervertebral discs

6. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Growth of Cartilage  Appositional – cells in the perichondrium secrete matrix against the external face of existing cartilage (outward)  Interstitial – lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within (upward)  Calcification of cartilage occurs  During normal bone growth  During old age

7. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bones and Cartilages of the Human Body Figure 6.1

8. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones  Axial skeleton – bones of the skull, vertebral column, and rib cage  Appendicular skeleton – bones of the upper and lower limbs, shoulder, and hip

9. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Long bones – longer than they are wide (e.g., humerus) Figure 6.2a

10. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Short bones  Cube-shaped bones of the wrist and ankle  Bones that form within tendons (e.g., patella) Figure 6.2b

11. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Flat bones – thin, flattened, and a bit curved (e.g., sternum, and most skull bones) Figure 6.2c

12. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Irregular bones – bones with complicated shapes (e.g., vertebrae and hip bones) Figure 6.2d

13. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of Bones  Support – form the framework that supports the body and cradles soft organs  Protection – provide a protective case for the brain, spinal cord, and vital organs  Movement – provide levers for muscles

14. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of Bones  Mineral storage – reservoir for minerals, especially calcium and phosphorus  Blood cell formation – hematopoiesis occurs within the marrow cavities of bones

15. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Markings  Projections, bulges, depressions, and holes that serve as:  Sites of attachment for muscles, ligaments, and tendons  Joint surfaces  Conduits for blood vessels and nerves

16. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Markings Table 6.1

17. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gross Anatomy of Bones: Bone Textures  Compact bone – dense outer layer  Spongy bone – honeycomb of trabeculae filled with yellow bone marrow

18. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone  Long bones consist of a diaphysis and an epiphysis  Diaphysis  Tubular shaft that forms the axis of long bones  Composed of compact bone that surrounds the medullary cavity  Yellow bone marrow (fat) is contained in the medullary cavity

19. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone  Epiphyses  Expanded ends of long bones  Exterior is compact bone, and the interior is spongy bone  Joint surface is covered with articular (hyaline) cartilage  Epiphyseal line separates the diaphysis from the epiphyses

20. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3

21. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3a

22. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3b

23. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3c

24. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Membranes  Periosteum – double-layered protective membrane  Outer fibrous layer is dense regular connective tissue  Inner osteogenic layer is composed of osteoblasts and osteoclasts  Richly supplied with nerve fibers, blood, and lymphatic vessels, which enter the bone via nutrient foramina  Secured to underlying bone by Sharpey’s fibers

25. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Membranes  Endosteum – delicate membrane covering internal surfaces of bone

26. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Short, Irregular, and Flat Bones  Thin plates of periosteum-covered compact bone on the outside with endosteum-covered spongy bone (diploë) on the inside  Have no diaphysis or epiphyses  Contain bone marrow between the trabeculae

27. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of a Flat Bone Figure 6.4

28. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Location of Hematopoietic Tissue (Red Marrow)  In infants  Found in the medullary cavity and all areas of spongy bone  In adults  Found in the diploë of flat bones, and the head of the femur and humerus

29. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone  Haversian system, or osteon – the structural unit of compact bone  Lamella – weight-bearing, column-like matrix tubes composed mainly of collagen  Haversian, or central canal – central channel containing blood vessels and nerves  Volkmann’s canals – channels lying at right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal

30. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone  Osteocytes – mature bone cells  Lacunae – small cavities in bone that contain osteocytes  Canaliculi – hairlike canals that connect lacunae to each other and the central canal

31. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6a, b

32. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6a

33. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6b

34. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6c

35. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Composition of Bone: Organic  Osteoblasts – bone-forming cells  Osteocytes – mature bone cells  Osteoclasts – large cells that resorb or break down bone matrix  Osteoid – unmineralized bone matrix composed of proteoglycans, glycoproteins, and collagen

36. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Composition of Bone: Inorganic  Hydroxyapatites, or mineral salts  Sixty-five percent of bone by mass  Mainly calcium phosphates  Responsible for bone hardness and its resistance to compression

37. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Development  Osteogenesis and ossification – the process of bone tissue formation, which leads to:  The formation of the bony skeleton in embryos  Bone growth until early adulthood  Bone thickness, remodeling, and repair

38. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Formation of the Bony Skeleton  Begins at week 8 of embryo development  Intramembranous ossification – bone develops from a fibrous membrane  Endochondral ossification – bone forms by replacing hyaline cartilage

39. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Intramembranous Ossification  Formation of most of the flat bones of the skull and the clavicles  Fibrous connective tissue membranes are formed by mesenchymal cells