Caption

Compact bone. Coloured scanning electron micrograph (SEM) of a transverse section of compact bone. The Haversian canals (dark circular holes) contain blood vessels, lymphatics and nerves (all coloured pink). Haversian canals are interconnecting neurovascular channels which run parallel to the long axes of long bones. Concentric bony layers, the lamellae, enclose the Haversian canals. The lamellae are made of compacted collagen fibres and ground substances produced by specialised cells called osteoblasts. During bone formation the osteoblasts become progressively trapped in lacunae (small dark pits). Magnification: x250 at5x7cm size.