1. SKELETAL SYSTEM Skeletal System

2. Support and movement Protection (brain, lungs) Mineral Storage of Calcium and Phosphate Red Blood Cell Production (long bones) Fat (Energy) Storage Functions of Skeletal System

3. Amount of bones in the human body: 206 Smallest bone: stirrup (middle ear) Largest bone: femur (thigh bone) longest, strongest, and heaviest bone supports much of our body weight Two Divisions: Axial skeleton and Appendicular skeleton SKELETAL SYSTEM

4. HUMAN SKELETON Front View (Anterior)Back View (Posterior)

5. Skull: Cranium Facial bones Sternum Vertebral column (spine) Ribs (Absent in frogs) Sacrum Axial Skeleton

6. Bones of the two girdles and their attached limbs Pectoral Girdle (Clavicle and Scapula) Upper Limb = Humerus Radius & Ulna, Carpals, Metacarpals & Phalanges Pelvic Girdle (coxal bones) Lower Limb = Femur Tibia & Fibula Tarsals, Metatarsals & Phalanges. Appendicular Skeleton tarsals metatarsals phalanges

7. Long Bone Section Tissues Epiphyses - ends Diaphysis - main shaft Epiphyseal Plates Cartilage lines where growth occurs Periosteum Outer, tough membrane Attachment for tendons and ligaments

8. Endosteum Membrane lining the medullary/marrow cavity Marrow Cavity Red Marrow - production of red blood cells (in spongy bone tissue) Yellow marrow - fat storage Articular Cartilage Between articulating bones cushions and protects bones Long Bone Section Tissues

9. Structure of Long Bone Compact Bone: Dense outer shell Osteon – (Haversian System) cylindrical unit rings of solid matrix with calcium and phosphate salts contains bone cells (osteocytes) central osteonic canal contains blood vessels

10. Histology of Bone Osteon Osteocyte in Lacunae Haversian (Osteonic) Canal with blood vessels Canaliculi (Canals that Connect lacunae)

11. Histology of Cartilage Matrix Chondrocytes in lacunae The Matrix is a composite of elastin and collagen Cartilage is avascular – cells rely on diffusion through the matrix for nutrients

12. Bone to Bone Bones connect to other bones at joints Connective tissue holds bones together –Ligaments for moveable joints –Cartilage for semi-movable joints (ribs)

13. Musculoskeletal System The skeleton and muscles function together as the musculoskeletal system Skeletal muscle: Attached to bones by tendons Moves bones Voluntary control