1. Chapter 5: The Skeletal System Lecture Notes Part B

2. Bone Fractures Fracture—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

3. Common Types of Fractures Table 5.2

4. Repair of Bone Fractures Hematoma (blood-filled swelling) is formed Break is splinted by fibrocartilage to form a callus Fibrocartilage callus is replaced by a bony callus Bony callus is remodeled to form a permanent patch Rickets: Disease in children where bones fail to calcify: Bones soften and weight bearing bones will bow Caused by lack of calcium or vitamin D

5. Stages in the Healing of a Bone Fracture Hematoma External callus Bony callus of spongy bone Healed fracture New blood vessels Internal callus (fibrous tissue and cartilage) Spongy bone trabecula Hematoma formation Fibrocartilage callus formation Bony callus formation Bone remodeling

6. Stages in the Healing of a Bone Fracture Figure 5.5, step 1 Hematoma Hematoma formation

7. Stages in the Healing of a Bone Fracture Figure 5.5, step 2 Hematoma External callus New blood vessels Internal callus (fibrous tissue and cartilage) Spongy bone trabecula Hematoma formation Fibrocartilage callus formation

8. Stages in the Healing of a Bone Fracture Figure 5.5, step 3 Hematoma External callus Bony callus of spongy bone New blood vessels Internal callus (fibrous tissue and cartilage) Spongy bone trabecula Hematoma formation Fibrocartilage callus formation Bony callus formation

9. Stages in the Healing of a Bone Fracture Figure 5.5, step 4 Hematoma External callus Bony callus of spongy bone Healed fracture New blood vessels Internal callus (fibrous tissue and cartilage) Spongy bone trabecula Hematoma formation Fibrocartilage callus formation Bony callus formation Bone remodeling

10. The Axial Skeleton Forms the longitudinal axis of the body Divided into three parts Skull Vertebral column Bony thorax

11. The Axial Skeleton Figure 5.6a

12. The Axial Skeleton Figure 5.6b

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

14. Human Skull, Lateral View Figure 5.7

15. Human Skull, Superior View Figure 5.8

16. Human Skull, Inferior View Figure 5.9

17. Human Skull, Anterior View Figure 5.11

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

19. Paranasal Sinuses Figure 5.10a

20. Paranasal Sinuses Figure 5.10b

21. The Hyoid Bone The only bone that does not articulate with another bone Serves as a moveable base for the tongue Aids in swallowing and speech

22. The Hyoid Bone Figure 5.12