Haversian Canals

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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 ?
Our study has shown that in rare cases Haversian canal has an eccentric position.
Secondary remodelling of the primary bone by dense Haversian tissue takes place in young adults and progress through ontogeny.
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.
If it is attained complete maturation, development of Haversian canals, blood vessels and medulla can be observed.
a result of a less pronounced Haversian system), leaving a clear separation between trabeculae and cortex, a feature often lacking in beluga bone.
a lamella in a Haversian canal around a bone cell, or a local region of a polymer that is known to have a larger microstructure).
Histological alteration of bone architecture is known to occur with a disorganization of the highly ordered Haversian system, a reduced number of resident osteocytes, and a reduced overall bone mass and density.
The cells of compact bone and the inorganic intercellular matrix in which they are suspended are organized around basic structural units called osteons or Haversian systems.
Osteoclastic resorption produces irregular scalloped cavities on the trabecular bone surface, called Howship lacunae, or cylindrical Haversian canals in cortical bone.
The quality assessment of the stained biopsy specimens has to yield each in a six step scale: 0: No bone; +: Few immature trabeculae with minimal contact to calcium phosphate; ++: Immature trabeculae with active osteoblasts and broad osteoid, biomaterial present; +++: Mature trabeculae, narrow osteoid, biomaterial present; ++++: Few areas of haversian bone, biomaterial grossly degraded; and +++++: Completely remodeled, no biomaterial.
These branches enter the Haversian canal and pass through the bone mainly running longitudinally.
Lacunae, canaliculi, and haversian canals of size varying from nano to micro meters, act as natural cavities.