1. Slide 0 Copyright © 2004. Mosby Inc. All Rights Reserved. Chapter 5 The Skeletal System

2. Slide 1 Copyright © 2004. Mosby Inc. All Rights Reserved. Functions of Bone Supports and gives shape to the body Protects internal organs Helps make movements possible Stores calcium Hemopoiesis- blood cell formation

3. Slide 2 Copyright © 2004. Mosby Inc. All Rights Reserved. Types of Bones Long—example: humerus (upper arm) Short—example: carpals (wrist) Flat—example: frontal (skull) Irregular—example: vertebrae (spinal cord)

4. Slide 3 Copyright © 2004. Mosby Inc. All Rights Reserved. Structural components  Diaphysis or shaft  Medullary cavity containing yellow marrow  Epiphyses or ends of the bone; spongy bone contains red bone marrow  Articular cartilage—covers epiphyses as a cushion  Periosteum—strong membrane covering bone except at joint surfaces  Endosteum—lines medullary cavity Structure of Long Bones (F 5-1)

5. Slide 4 Copyright © 2004. Mosby Inc. All Rights Reserved. Microscopic Structure of Bone and Cartilage Bone types  Spongy  Texture results from needlelike threads of bone called trabeculae surrounded by a network of open spaces  Found in epiphyses of bones  Spaces contain red bone marrow  Compact  Structural unit is haversian system—composed of concentric lamella, lacunae containing osteocytes and canaliculi, all covered by periosteum (Cont’d…)

6. Slide 5 Copyright © 2004. Mosby Inc. All Rights Reserved.

7. Slide 6 Copyright © 2004. Mosby Inc. All Rights Reserved. Microscopic Structure of Bone and Cartilage (…Cont’d) Cartilage  Cell type called chondrocyte  Matrix is gel-like and lacks blood vessels F 5-4

8. Slide 7 Copyright © 2004. Mosby Inc. All Rights Reserved. Bone Formation and Growth (F 5-5) Sequence of development early—cartilage models replaced by calcified bone matrix Osteoblasts form new bone, and osteoclasts resorb bone

9. Slide 8 Copyright © 2004. Mosby Inc. All Rights Reserved. Newborn & Late Development Newborn have a highly cartilaginous skeleton for breaching the birth canal The skull is the limiting factor in human head size and brain capacity After adolescent ossification bone growth continues until ossification of the epiphyseal plate is ossified F 5-6

10. Slide 9 Copyright © 2004. Mosby Inc. All Rights Reserved. Division of Skeleton Skeleton composed of the following divisions and their subdivisions: F 5-7&8 Axial skeleton  Skull  Spine  Thorax  Hyoid bone

11. Slide 10 Copyright © 2004. Mosby Inc. All Rights Reserved. Division of Skeleton (…Cont’d) Appendicular skeleton  Upper extremities, including shoulder girdle  Lower extremities, including hip girdle Location and description of bones

12. Slide 11 Copyright © 2004. Mosby Inc. All Rights Reserved. Differences Between a Man’s and a Woman’s Skeleton (F 5-18) Size—male skeleton generally larger Shape of pelvis—male pelvis deep and narrow, female pelvis broad and shallow Size of pelvic inlet—female pelvic inlet generally wider, normally large enough for baby’s head to pass through it Pubic angle—angle between pubic bones of female generally wider

13. Slide 12 Copyright © 2004. Mosby Inc. All Rights Reserved. (F 5- 18)

14. Slide 13 Copyright © 2004. Mosby Inc. All Rights Reserved. Joint (Articulations) Kinds of joints (F 5-19)  Synarthrosis (no movement)—fibrous connective tissue grows between articulating bones; for example, sutures of skull  Amphiarthrosis (slight movement)—cartilage connects articulating bones; for example, symphysis pubis

15. Slide 14 Copyright © 2004. Mosby Inc. All Rights Reserved. Joint (Articulations)  Diarthrosis (F 5-20) (free movement)—most joints belong to this class  Structures of freely movable joints—joint capsule and ligaments holding adjoining bones together but permit movement at joint  Articular cartilage—covers joint ends of bones and absorbs joints  Synovial membrane—lines joint capsule and secretes lubricating fluid  Joint cavity—space between joint ends of bones

16. Slide 15 Copyright © 2004. Mosby Inc. All Rights Reserved. Diarthrotic Joint Types (F 5-21)  Types of freely movable joints—ball-and-socket, hinge, pivot, saddle, gliding, and condyloid

17. Slide 16 Copyright © 2004. Mosby Inc. All Rights Reserved. On To Bone Growth & Repair!!