1. Overview of System: Functions, Bone Classification Pages 134-136

2.  Two subdivisions of the skeleton 1.Axial skeleton 2.Appendicular skeleton  Parts that make up the skeletal system ◦ Bones (skeleton) ◦ Joints ◦ Cartilages ◦ Ligaments © 2015 Pearson Education, Inc.

3.  Bone anatomy reflects the demands placed on the bone: ◦ Compression ◦ Tension/Pulling forces ◦ Storage compartments

4.  Support the body  Protect soft organs ◦ Skull and vertebrae protect brain and spinal cord ◦ Rib cage protects thoracic cavity organs  Attach skeletal muscles to allow movement  Store minerals and fats ◦ Calcium and phosphorus ◦ Fat in the internal marrow cavity  Blood cell formation (hematopoiesis) © 2015 Pearson Education, Inc.

5.  The adult skeleton has 206 bones  Two basic types of bone tissue ◦ (What type of tissue makes bone?) 1.Compact bone  Dense, smooth, and homogeneous  Provides storage and strength 2.Spongy bone  Small needle-like pieces of bone  Many open spaces  Provides flexibility while being strong and lightweight © 2015 Pearson Education, Inc.

6. Spongy bone Compact bone

7.  Bones are classified on the basis of shape, as: ◦ Long ◦ Short ◦ Flat ◦ Irregular © 2015 Pearson Education, Inc.

8. (a) Long bone (humerus) (b) Irregular bone (vertebra), right lateral view (d) Short bone (talus) (c) Flat bone (sternum)

9.  Long bones ◦ Typically longer than they are wide ◦ Shaft with heads situated at both ends ◦ Contain mostly compact bone ◦ All of the bones of the limbs (except wrist, ankle, and kneecap bones) are long bones ◦ Examples:  Femur, tibia, fibula  Humerus, radius, ulna © 2015 Pearson Education, Inc.

10. (a) Long bone (humerus)

11.  Short bones ◦ Generally cube-shaped ◦ Contain mostly spongy bone ◦ Include bones of the wrist and ankle ◦ Sesamoid bones are a type of short bone that form within tendons (patella) ◦ Examples:  Carpals  Tarsals  Metacarpals/Metatarsals/Phalanges © 2015 Pearson Education, Inc.

12. (d) Short bone (talus)

13.  Flat bones ◦ Thin, flattened, and usually curved ◦ Two thin layers of compact bone surround a layer of spongy bone ◦ Examples:  Skull  Ribs  Sternum © 2015 Pearson Education, Inc.

14. Spongy bone Compact bone

15. (c) Flat bone (sternum)

16.  Irregular bones ◦ Irregular shape ◦ Do not fit into other bone classification categories ◦ Examples:  Vertebrae  Hip bones © 2015 Pearson Education, Inc.

17. (b) Irregular bone (vertebra), right lateral view