Overview
This lecture covers the structure and key components of compact bone, focusing on its organization and terminology.
Bone Coverings
- The periosteum is a connective tissue covering that surrounds all bones.
- Perforating fibers, also called Sharpey's fibers, connect the periosteum to the underlying bone.
- The endosteum is a membrane lining the medullary cavity inside the bone.
Compact Bone Structure
- Compact bone is made of circular structures called osteons, each with a central canal.
- The central canal runs through the middle of each osteon and contains blood vessels and nerves.
- Perforating canals, or Volkman's canals, connect central canals and run perpendicular to them.
Small Bone Features
- Lacunae are small cavities within bone tissue that house osteocytes (bone cells).
- Canaliculi are tiny channels radiating from lacunae, allowing communication and nutrient exchange between osteocytes.
Osteon Details
- Osteons are composed of concentric rings of bone called lamellae.
- Lamellae are layers of bony material surrounding the central canal within each osteon.
Key Terms & Definitions
- Periosteum â Connective tissue layer covering the outer surface of bone
- Perforating (Sharpey's) fibers â Fibers connecting periosteum to the bone
- Endosteum â Membrane lining the inside (medullary cavity) of bone
- Osteon â Circular structural unit of compact bone
- Central canal â Central tube in the osteon containing blood vessels and nerves
- Perforating (Volkman's) canal â Canal connecting central canals across osteons
- Lacuna (plural: lacunae) â Small cavity housing an osteocyte
- Canaliculi â Small channels connecting lacunae
- Osteocyte â Mature bone cell found in lacunae
- Lamella (plural: lamellae) â Concentric ring/layer of bone within an osteon
Action Items / Next Steps
- Review bone structure models to identify each feature discussed.
- Study key term definitions for upcoming quizzes.