Haversian Canals

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Related to Haversian: Haversian system, canaliculi, Volkmann's canal

Haversian Canals

 

(named for the English anatomist C. Havers, 1650-1702), tubular cavities in the compact matter of lamellar bone in higher vertebrates and humans. In hollow bones the Haversian canals run parallel to the longitudinal axis, in flat ones parallel to the surface, and in the bodies of the vertebrae perpendicular to the axis. Each Haversian canal is surrounded by concentrically placed bony plates (lamellae); together they form a structural unit of the bone, the Haversian system. Between lamellae in the cavities there are bone cells—osteocytes.

Inside the Haversian canals are blood vessels, nerves, and mesenchymal cells, which, in the rebuilding of bone, form osteoclasts, which resolve bone, and osteoblasts, which manufacture it. Small canals thread through the osteal lamellae and open into the Haversian canals, uniting the osteal cavities. Haversian canals of neighboring systems for some distance may unite into stable supporting structures.

V. I. KANTOROVA

References in periodicals archive ?
Soft tissue extension in Case 2 was very small and occurred by invasion of the periosteum by linear rows of tumor that permeated through Haversian canal-like channels (Fig.
2) This is followed by microscopic permeation of the Haversian and Volkmann's canals, with cortical destruction (57% of CHS on radiographs).
Based on our limited experience, it appears that in the femoral diaphysis there are at least two different mechanisms of bone destruction with soft tissue extension: first, one in which the tumor destroys the cortex and periosteum, recognized on MRI by endosteal scalloping, cortical destruction, and soft tissue extension (Case 1); and, second, a type of soft tissue extension where the tumor permeates into the periosteum through haversian canal-like channels in a microscopic linear fashion, which it difficult to recognize on MRI, as in our Case 2.
The lamellar bone showed a well-developed haversian system and fatty bone marrow.
The basic functional unit of mature compact bone is the osteon or Haversian system.
The rabbit as an experimental animal was chosen on the basis that it has a very well defined cortical bone Haversian system and the stimulation of remodeling after injury is more similar to that of other larger animals.
Natural cavities such as lacunae, canaliculi and haversian canals can also possibly initiate cracks when bone is subjected to high strain rates (2).
However, the interlayer thickness cannot be so small in the case of bone because the size of the bone sample to be tested should be large enough to be characteristic of the material, with several haversian canals, lacunae, etc.
At the end of 9 weeks after surgery, osteogenic and osteolytic activities are observed with remodeling of Haversian system (fig.