6.4: microscopic anatomy of bone

Osteoprogenitor cells

Bone stem cells.

Osteoblasts

Bone cells that secrete bone matrix.

Osteocytes

Bone cells that monitor and maintain bone matrix.

Bone lining cells

Cells that monitor and maintain bone matrix.

Osteoclasts

Bone cells involved in bone resorption.

Osteon

The structural unit of compact bone; also called the Haversian system.

Haversian system

Another name for an osteon.

Lamellae

Concentric tubes of bone matrix that make up an osteon.

Central canal

A canal running through the center of an osteon that allows blood vessels and nerves to pass through.

Perforating canals

Also called Volkmann's canals; they run at right angles to the long axis of bone and connect blood and nerve supplies.

Volkmann's canals

Another name for perforating canals.

Lacunae

Small spaces that house osteocytes.

Canaliculi

Hair-like channels that connect lacunae to each other and to the central canal.

Circumferential lamellae

Lamellae located just beneath the periosteum that extend around the entire circumference of the bone.

Interstitial lamellae

Lamellae located between intact osteons.

Spongy bone

Unlike compact bone, spongy bone lacks osteons and has trabeculae that align along lines of stress.