Bone: the organ, compact bone
Compact bone forms the majority of the diaphysis and is seen in longitudinal section of a decalcified bone preparation (above right) and in a ground bone preparation (below right). Haversian systems (osteons), are oriented longitudinally in the shaft and comprise most of the shaft’s width, providing great strength to resist vertical stress. 100x, 200x
Haversian systems >
Haversian systems are better seen in the ground bone section, where the organization of the matrix is more clearly visible.
Haverian canals >
Haversian canals are centrally located in each osteon and possess a blood vessel needed for maintenance of the bone. Branches of these vessels travel in horizontally-oriented Volkmann’s canals. Both Haversian and Volkmann’s canals are lined by endosteum which is continuous with the endosteum of the marrow cavity.
Volkmann's canals
Haversian canals are centrally located in each osteon and possess a blood vessel needed for maintenance of the bone. Branches of these vessels travel in horizontally-oriented Volkmann’s canals. Both Haversian and Volkmann’s canals are lined by endosteum which is continuous with the endosteum of the marrow cavity.
Nutrient vessel >
A nutrient vessel is visible entering from the marrow cavity. The space it occupies is lined by endosteum.
Endosteum >
The endosteum lines the marrow cavity and also extends to line the nutritive foramen, Haversian canals and Volkmann’s canals. Endosteum is not present in lacunae or canaliculi.
Circumferential lamellae >
Compact bone is also be deposited in layers on exterior and interior bony surfaces, forming circumferential lamellae.
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