Overview
This lecture covers the basic anatomical structures of a long bone, identifying key regions and tissues with their functions.
Major Parts of a Long Bone
- The middle shaft of a long bone is called the diaphysis.
- The ends of a long bone are called epiphyses (singular: epiphysis).
Coverings and Cavities
- The outer surface of bone is covered by tough connective tissue called the periosteum.
- Inside the diaphysis is a hollow space called the medullary cavity.
- The medullary cavity contains yellow bone marrow, which stores fats (lipids).
Types of Bone Tissue
- The hard, dense tissue along the sides of the diaphysis is called compact bone.
- The porous bone found within the epiphyses is called spongy bone.
- Spongy bone contains red bone marrow, which produces blood cells.
Additional Structures
- Articular cartilage is a layer of hyaline cartilage covering the ends of the bone, providing protection.
- Epiphyseal plates (growth plates) are dense areas at the ends of bones, remnants from bone growth.
Key Terms & Definitions
- Diaphysis — the long, central shaft of a long bone.
- Epiphysis — the end part of a long bone.
- Periosteum — tough, fibrous connective tissue covering the bone’s outer surface.
- Medullary cavity — hollow space within the diaphysis, containing yellow bone marrow.
- Yellow bone marrow — tissue in the medullary cavity, storing fat.
- Compact bone — dense, solid bone forming the outer layer.
- Spongy bone — porous bone tissue found in the epiphyses, containing red bone marrow.
- Red bone marrow — tissue in spongy bone making blood cells.
- Articular cartilage — layer of hyaline cartilage covering bone ends for protection.
- Epiphyseal plate — growth plate area at the ends of long bones.
Action Items / Next Steps
- Review and label diagrams of a long bone, identifying each part listed above.