Bone Histology and Growth Plate Zones

Vocabulary flashcards covering key terms related to osteon structure and the zones of the epiphyseal (growth) plate.

Canaliculi

Microscopic channels that connect neighboring lacunae, allowing osteocytes to exchange nutrients and waste with the blood supply.

Central Canal (Haversian Canal)

Longitudinal channel at the center of an osteon that contains blood vessels and nerves.

Osteon

The cylindrical structural unit of compact bone composed of concentric lamellae surrounding a central canal.

Osteocyte

A mature bone cell that resides in a lacuna and helps maintain the bone matrix.

Lacuna

A small cavity within the bone matrix that houses an osteocyte.

Concentric Lamella

Ring-like layers of calcified matrix that surround the central canal within an osteon.

Epiphyseal Plate (Growth Plate)

A layer of hyaline cartilage between the epiphysis and diaphysis responsible for longitudinal bone growth.

Resting Zone

Region of the epiphyseal plate closest to the epiphysis containing relatively inactive chondrocytes.

Proliferative Zone

Zone where chondrocytes rapidly divide and form columns, pushing the epiphysis away from the diaphysis to lengthen the bone.

Hypertrophic Zone

Zone where chondrocytes enlarge, and their lacunae begin to erode, thinning surrounding cartilage.

Calcification Zone

Zone where the cartilage matrix calcifies, chondrocytes die, and blood vessels invade the area.

Ossification Zone

Zone where osteoblasts deposit bone matrix on calcified cartilage spicules, resulting in new bone formation.