1. Skeletal System

2. What is included in skeletal system? • Bones • Ligaments (bone to bone) • Tendons (bone to muscle)

3. Bone Function • Support • Protection • Movement • Blood cell formation • Inorganic salt storage

5. A closer look at bone tissue

6. Spongy vs. Compact Bone Spongy bones don’t have concentric circles, but trabeculae (sheets/spikes)

7. Components of all bone tissue • Organic Components (35%) • Osteocytes • Osteoclasts-resorption • Collagen (main component) • Gives bone strength and resilience

8. Components of Bone Tissue B. Inorganic components (65%) 1. Mineral salts = calcium and phosphorus a. make bone hard and resistant to crushing

9. Types of Bones • Long Bone • Diaphysis/Shaft • Epiphyses/Heads • Epiphyseal line • Periostenum • Nutrient Foramen • Articular cartilage Examples?

10. Types of Bones 2. Short Bone

11. Type of Bone 3. Flat Bones Examples?

12. Types of Bones 4. Irregular Bones

13. Osteogenesis/Ossification • Embryos have only connective tissue “skeletons,” no bone • Ossification begins at 6-7 weeks • 2 Mechanisms: • Intramembranous ossification • Endochondral ossification

14. Intramembranous Calcification • Originate from sheetlike layers of connective tissue

15. Endochondral Ossification • Originate from masses of connective tissue

17. Through infancy and childhood, growth occurs at epiphyseal plate

18. Ossification Timetable

20. Bone Remodeling and Repair

21. Bone Remodeling • Controlled by: • Parathyroid hormone (stimulates osteoclasts) • Calcitonin (inhibits osteoclasts)

22. What do you need for proper growth and remodeling? • Minerals • Vitamins • Hormones • HGH • Sex hormones • PT • Calcitonin

23. How does exercise affect your bones? • Mechanical Stress causes increased deposition of mineral salts and productions of collagen fibers • Makes bones stronger