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 ?
In some cases, osteon cluster has been seen, and enclosing of two and sometimes three osteons with common Haversian plates has been noted.
All the bones exhibit a mature histomorphology, characterized at least by a combination of three or more of the following characters: (i) extensive remodelling of the primary cortex by dense Haversian bone; (ii) presence of an outermost layer of highly organized, slow-growing primary bone, poorly vascular, with mature primary osteons; (iii) presence of growth rings which denote that the animal reached sexual maturity and lived for years; (iv) presence of a nonvascularized external fundamental system (EFS) at the periosteal surface, and (v) the presence of a greatly expanded medullar cavity lined by endosteal bone (Horner et al., 1999; Chinsamy-Turan 2005 and references therein; Klein and Sander, 2008).
(11) There has been research to also indicate the nutrient rich Haversian canals within bone can act as pain-sensitive structures (29), allowing for deep-seated bone pain in daily activities.
From the 30th to the 90th POD, the defect margins presented a compact bone structure with haversian systems and osteocytes (Figures 2 and 3).
Exudates were spread between bone trabecules and penetrated into Haversian channels.
The cortical microstructure contains Haversian canals, lacunae and vascular canals, which are defined as pores or cavities of the cortical bone.
In their turn, intra-osteon potentials obtained are uneven: a potential decrease has been observed at the level of Haversian canals, close to the compressed side, and their growth on the opposite, tensioned side of the bone.
Histological examination of this specimen revealed metaplastic ossification to lamellar bone with eosinophilic ossified matrix, lacunar spaces and haversian vascular canals characteristic of bone (Fig.
It consists of a network of lamellae parallel to each other mostly known as Haversian canals.