Bones
1. Describe the structure and functions of bones
Bones are the hardest substance in the human body, composed of 25–30% organic material (collagen and other proteins) and 70–75% inorganic material (minerals like calcium and phosphorus). They provide structure, support, and protection to the body.
Types:
- Long bones → shaft (diaphysis) + two ends (epiphyses)
- Short bones → cube-shaped (e.g., carpal bones)
- Flat bones → e.g., skull, ribs
- Irregular bones → e.g., vertebrae
Functions:
- Support and movement
- Protection of vital organs
- Blood cell production (bone marrow)
- Mineral storage
2. Classify bones (examples)
Long bones: Femur, Humerus, Radius, Ulna, Tibia, Fibula
Short bones: Carpal bones, Tarsal bones, Phalanges
3. Describe the parts of a growing long bone
- Diaphysis → shaft
- Epiphyses → both ends (covered by articular cartilage)
- Metaphysis → region between diaphysis and epiphysis (contains growth plate)
4. Explain the blood supply of long bone
- Nutrient (Diaphyseal) artery → enters through nutrient foramen → supplies medullary cavity & diaphysis
- Metaphyseal arteries → supply metaphysis
- Epiphyseal (End) arteries → supply epiphysis
Diagram: Structure of Long Bone (100% copyright-free, Public Domain)
Diagram: Blood Supply of Long Bone (100% copyright-free, Public Domain)
