Overview
This lecture reviews the microscopic structure of compact bone, focusing on identifying key features observed under various magnifications.
Microscopic Structure of Compact Bone
- Compact bone is studied under different magnifications: low, medium, and high power.
- The main structural unit of compact bone is the osteon.
- The osteon has a central hole called the central canal.
- Dark spots observed under the microscope are called lacunae.
- Each lacuna contains a bone cell known as an osteocyte.
- Thin dark lines radiating from lacunae are canaliculi, small channels for cell communication.
- Bone material forms layers around the central canal; each layer is called a lamella.
Key Terms & Definitions
- Osteon â Cylindrical structure in compact bone containing a central canal.
- Central Canal â Hollow center of an osteon that contains blood vessels and nerves.
- Lacuna (plural: lacunae) â Small cavity in bone matrix housing an osteocyte.
- Osteocyte â Mature bone cell located within a lacuna.
- Canaliculus (plural: canaliculi) â Tiny channels connecting lacunae and allowing communication between osteocytes.
- Lamella (plural: lamellae) â Concentric rings of bone matrix surrounding the central canal.
Action Items / Next Steps
- Review labeled diagrams of compact bone to identify osteons, central canals, lacunae, osteocytes, canaliculi, and lamellae.