1. The Skeletal System All parts are connective tissue: Bones (skeleton)
Cartilages
Ligaments
two divisions:
Axial skeleton
Appendicular
skeleton
Axial skeleton in green, appendicular in yellow. From appendage

2. Functions of Skeleton and Bones
Support of the body
Protection of soft organs
Movement due to attached skeletal muscles
Storage of minerals and fats
Blood cell formation

3. Bones of the Human Body 206 bones Two basic types Compact bone Dense
Calcium crystals
Spongy bone
Trabeculae - “little beams”
Many open spaces
Figure 5.2b

4. Gross Anatomy of a Long Bone
Epiphysis
Ends of the bone - spongy bone
Red bone marrow
Diaphysis
Shaft - compact bone
Medullary cavity
Periosteum
Figure 5.2a

5. Structure of Bone
Osteon - cylinder of bone, has central canal with blood vessels
Osteocytes within spaces (lacunae), connected by small canals (canaliculi)
Figure 5.1

6. Cartilage and Ligaments
Ligaments - dense fibrous connective tissue
Collagen fibers, fibroblasts
Cartilage - collagen and elastin fibers in base of water. Smooth and flexible substance
used to reduce friction, provide support under pressure at joints

7. Changes in the Human Skeleton
Embryos - hyaline cartilage
Cartilage replaced by bone = ossification
done by osteoblasts - bone building cells
Secrete osteoid (proteins, fibers, enzymes)
Osteoid replaced by calcium phosphate salts
Cartilage remains in nose, ribs, joints, and epiphyseal plates, ends of bones

8. Bone Development (cont.)
Figure 5.2

9. Types of Bone Cells Chondrocytes Cartilage-forming cells Osteocytes
Mature bone cells
Osteoblasts
Bone-forming cells
Osteoclasts
Bone-destroying cells
Break down bone matrix for remodeling and release of calcium

10. Mature Bone Remodeling and Repair
Changes in shape, size, strength
Dependent on diet, exercise, age
Bone cells regulated by hormones
Parathyroid hormone (PTH): removes calcium from bone
Calcitonin: adds calcium to bone

11. Stages in the Healing of a Bone Fracture
Fibrocartilage callus is replaced by a bony callus
Bony callus is remodeled to form a permanent patch
Hematoma (blood-filled swelling) is formed
Break is splinted by fibrocartilage to form a callus
Figure 5.5

12. The Axial Skeleton Forms the longitudinal part of the body
Divided into 3 parts
Skull
Vertebral column
Bony thorax

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. The Hyoid Bone only bone that does not articulate with another bone
Serves as moveable base for the tongue
Attached via ligaments to temporal bones. Anchor for the muscles attached to larynx .
Figure 5.12

15. Paranasal Sinuses Functions of paranasal sinuses Lighten the skull
Give resonance and amplification to voice
Figure 5.10

16. The Fetal Skull
Fontanelles – fibrous membranes connecting the cranial bones
Allow the brain to grow
Convert to bone within 24 months after birth
Figure 5.13

17. The Vertebral Column 5 regions, 33 bones Spine has a normal curvature
Vertebrae separated by intervertebral discs
Figure 5.7

18. The Bony Thorax Made-up of two parts Sternum Ribs (12 pr)
Forms a cage to protect major organs
Figure 5.19a

19. The Appendicular Skeleton
Limbs (appendages)
Pectoral girdle
Pelvic girdle

20. Bones of the Pectoral Girdle
Clavicle – collarbone
Scapula – shoulder blade
Figure 5.20a–b

21. Bones of the Upper Limb The arm - Humerus The forearm - Ulna
and Radius
Hand -
Carpals
Metacarpals
Phalanges
Figure 5.21a–b

22. The Pelvis
Figure 5.23a

23. Gender Differences of the Pelvis
Figure 5.23c

24. Bones of the Lower Limbs
Femur – thigh bone
Tibia - bears weight
Fibula - helps rotation with ankle
Tarsals - ankle
Metatarsals - foot
Phalanges - toes
Figure 5.24a–b

25. Joints (Articulations)
Classified by degree of movement
Fibrous joint: immovable; e.g., fontanels
Cartilagenous joint: slightly movable, cartilage connection; e.g., backbone
Synovial joint: freely movable

26. Synovial Joints - movable; all limbs
Joint capsule: synovial membrane + hyaline cartilage
Synovial membrane secretes synovial fluid as lubricant
Hyaline cartilage cushions

27. Disorders, Inflammatory Conditions Associated with Joints
Sprains: stretched or torn ligaments
Bursitis and tendinitis: inflammations
Arthritis: inflammation of joints
Over 100 different types
The most widespread crippling disease in the United States

28. Clinical Forms of Arthritis
Osteoarthritis
Cartilage wears out, pain, inflammation
normal aging processes
Rheumatoid arthritis
autoimmune disease –attacks the joints
Symptoms begin with inflammation of synovial membranes
Cartilage lost, bones fused, leads to deformities