Architecture of long and lamellar bones

knob at either end; composed of spongy bone covered by a thin rim of compact bone

Epiphysis

shaft of the long bone almost totally composed of compact bone; hollow center lined with thin region of spongy bone, containing marrow

Diaphysis

flared region between diaphysis & epiphysis

Metaphysis

hyaline cartilage separating epiphysis & metaphysis; region of endochondral bone formation

Epiphyseal plate

Refers to the complex of concentric lamellae (4-20 in number) arranged around a central canal (haversian canal) containing blood vessels, nerves, CT and endosteum

Osteon Or Haversian System

Spaces located between successive lamellae which contain a single osteocyte and interconnected by canaliculi

Lacunae

Narrow tunnels between lamellae which contain cytoplasmic processes of osteocytes

Canaliculi

Outer boundary of each osteon

Cement Line

Irregular groups of parallel lamellae in between intact osteons which represent partially destroyed osteons by osteoclasts during growth and remodelling of bone

Interstitial lamellae

Located immediately beneath the periosteum

External (or outer) circumferential lamellae

Located around the marrow cavity

Internal (or inner) circumferential lamellae

Transverse canals which allow central canals to communicate with one another and with the marrow cavity and periosteum

Perforating or volkmann canals