Compact bone. Coloured scanning electron micrograph (SEM) of a transverse section of compact bone. The Haversian canal (dark central area) contains blood vessels, lymphatics and nerves (all coloured red). 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 areas). Magnification: x315 at 6x7cm size. x740 at 8x6,x395 at 10x7cm master size"