Microscopic Anatomy of Bone

Periosteum

The outer layer of bone made of tough connective tissue, involved in muscle attachment and bone repair.

Compact Bone

A thick layer of bone beneath the periosteum, organized into cylinders called osteons.

Spongy Bone

Bone with a lattice-like structure made of trabeculae, found at the ends of long bones and containing marrow.

Trabeculae

Tiny beams that form the lattice-like structure of spongy bone, arranged along lines of stress.

Osteons

Cylinders that make up compact bone, consisting of concentric rings called lamellae.

Central Canal (Haversian Canal)

The canal at the center of osteons that contains blood vessels and nerves.

Perforating Canals (Volkmann’s Canals)

Canals that connect central canals, running perpendicular to them.

Osteocytes

Mature bone cells that make up most of the bone tissue.

Osteoclasts

Bone cells that break down old bone tissue.

Osteoblasts

Bone cells that produce new bone tissue.

Canaliculi

Tiny channels that connect all bone cells, allowing nutrient and waste exchange.

Difference between Spongy and Compact Bone

Spongy bone has open spaces and a lattice structure, while compact bone is tightly packed and organized into osteons.