The Skeletal System

1. Chapter 6-7 The Skeletal System

2. Objectives • Distinguish between bones of the axial skeleton and the appendicular skeleton. • Identify major markings (such as foramina, fossae, tubercles, etc.) on a skeleton. Explain why these markings are important.

3. An Introduction to the Skeletal System • Components • Bone • Cartilage • Ligaments (bone to bone) • Tendons (muscle to bone) • Joints

4. Epiglottis Larynx Thyroid cartilage Cartilage in external ear Cartilages in nose Trachea Cricoid cartilage Lung Articular Cartilage of a joint Cartilage in Intervertebraldisc Costal cartilage Respiratory tube cartilages in neck and thorax Bones of skeleton Pubic symphysis Axial skeleton Meniscus (padlike cartilage in knee joint) Appendicular skeleton Cartilages Articular cartilage of a joint Hyaline cartilages Elastic cartilages Fibrocartilages

5. Axial Skeleton • 80 bones

6. AppendicularSkeleton • 126 bones

7. Functions • Support • Storage of minerals and lipids • Blood cell production • Protection • Leverage

8. The Gross Anatomy of Bones • 206 bones in adults • Bone shapes: • Long bones • Irregular bones • Flat bones • Short bones

9. Parietal bone Occipital bone Frontal bone of skull Mandible Clavicle Scapula Radius Ulna Ribs Humerus Vertebra Ilium Tibia Femur

11. Long Bones • Long and thin • Found in arms, legs, hands, feet, fingers, and toes

12. Irregular Bones • Have complex shapes • Spinal vertebrae, pelvic bones

13. Flat Bones • Thin with parallel surfaces • Found in the skull, sternum, ribs, and scapula

14. Short Bones • Small and thick • Ankles, wrist bones

15. Bone Markings • Sites of muscle, ligament, and tendon attachment • Tuberosity • Large, rounded projection • Crest • Narrow, prominent ridge • Trochanter • Large, blunt, irregularly shaped process • Found only in the femur

16. Bone Markings • Tubercle • small rounded projection • Epicondyle • raised area above a condyle • Spine • sharp, slender, often pointed projection • Process • any bony prominence

17. Tuberosity

18. Crest

19. Trochanter

20. Tubercle

21. Epicondyle

22. Spine

23. Process

25. The Dynamic Nature of Bone • The adult skeleton: • Maintains itself • Replaces mineral reserves • Remodeling: • Recycles and renews bone matrix • Involves 3 types of bone cells

26. Effects of Exercise on Bone • Mineral recycling allows bones to adapt to stress • Heavily stressed bones become thicker and stronger

27. Hormonal and Nutritional Effects on Bone • Normal bone growth and maintenance requires nutritional and hormonal factors • Minerals: calcium, phosphate salts, magnesium, fluoride, iron, manganese

28. The Skeleton as a Calcium Reserve • Bones store calcium and other minerals • Calcium is the most abundant mineral in the body

29. Fracture Repair • Fractures: cracks/breaks in bone • Repaired in 4 steps: • 1) hematoma forms (blood clot) • 2) callus forms, cell division • 3) bony callus forms • 4) bone remodeling

30. Hematoma 1 A hematoma forms.

31. Externalcallus Internalcallus(fibroustissue andcartilage) Newbloodvessels Spongybonetrabecula 2 Fibrocartilaginouscallus forms. Figure 6.15, step 2

32. Bonycallus ofspongybone 3 Bony callus forms. Figure 6.15, step 3

33. Healedfracture 4 Bone remodelingoccurs. Figure 6.15, step 4

34. Aging and the Skeletal System • Bones become thinner and weaker • Begins between ages 30 to 40 • Women lose 8% of bone mass per decade; men 3%