Anatomy Unit 4 Notes: Bone Types, Function, The Skeleton
- 1. ANATOMY UNiT 4 NOTes: BONe TYpes & COMpOsiTiO N
- 2. (1) Skeletal Parts • Bones • Joints • Cartilage • Marrow
- 3. (2) Skeletal Function 1. Support – Framework for posture – Limbs act as pillars – Rib cage supports thoracic wall 1. Protection - Ribs protect lungs and heart - Skull protects brain - Vertebrae protect spinal cord 1. Movement - Attachment sites for muscles and tendons - Muscles use bones as levers - Joints between allow for range of motion
- 4. …Function Cont’d… 4. Mineral & Growth Factor Storage - Reservoir for calcium and phosphate - Releases minerals into blood - Growth factors (insulin, transforming factor, morphogenic proteins) in bone 5. Blood Cell Formation - Marrow within cavities of bones (primarily long) - Marrow initiates hematopoeisis (blood cell formation)
- 5. (3) How are bones hinged together? • Joints: Connection between two bones. – Filled with cartilage (padding) • Allow for wider range of movement. – Circular – Angular • Reduce rigidity of bone structure. • *Cartilage within joints (in between bones) provides shock absorption, and decreases friction.
- 6. (4) What are the Bone Regions? • Axial – Down the center of body – Skull, vertebral column, rib cage, center pelvis • Appendicular – Off the sides of body – Upper and lower limbs, shoulder and hip bones
- 8. (5) What are the types of bones? • Long • Short • Flat • Irregular
- 10. (6) Long Bones • Longer than they are wide • Has a shaft and 2 ends • Weight bearing bones (like steel beams) • Provide the greatest structure and support • Examples: – All limb bones – Except…. Kneecap, Wrist and Ankle bones
- 12. (7) Short Bones • Cube Shaped • Allow for wider range of movement • Examples: – Wrist – Ankle
- 14. (8) Flat Bones • Thin, flat and curved • Protect soft tissue (like plates of armor) • Examples: – Sternum – Shoulder blades – Ribs – Skull bones
- 16. (9) Irregular Bones • Complicated, unusual shapes • Muscles, tendons, ligaments usually attach to these • Examples: – Vertebrae – Hip bones
- 18. (10) Bone Structure • Unique based on location + bone type. • Compact Bone (Outer Layer): – Dense – Smooth and Solid to naked eye • Spongy Bone (Inner Layer): – Hole-y (like a honeycomb) – Made of small needle-like, flat pieces called “trabeculae” – Open spaces between trabeculae are filled with red or yellow bone marrow
- 21. (11) Structure of a Long Bone • Diaphysis: – Center, main shaft – Long part of bone – Made of very thick compact bone surrounding a central marrow cavity • Epiphysis: – Ends of bone – Wider than diaphysis – Made of compact bone which surrounds spongy bone. – Joint surface of each epiphysis is covered with hyaline cartilage
- 22. • Epiphyseal Line: – Remnant of Epiphyseal Plate – Found in adult bones – Shows amount of cartilage growth during adolescence • Membranes: – Periosteum = Around the outside • Richly supplied with nerve fibers, lymphatic vessels and blood vessels • Provides anchoring points for tendons and ligaments – Endosteum = Around the inside • Surrounds the spongy bone
- 24. (12) Chemical Composition of Bone • Contains organic & inorganic components • Organic: – Cells (osteoblasts, osteocytes, osteoclasts) – Osteoid • Made of glycoproteins and collagen fibers • Secreted by osteoblasts • “filler matrix” around cells – Contribute to flexibility and tensile strength • Inorganic: – Mineral Salts (calcium phosphates) – Contribute to hardness of bone (allowing for compression resistance)