BONE HISTOLOGY LAB  ©David B. Fankhauser, Ph.D. Professor of Biology and Chemistry University of Cincinnati Clermont College, Batavia OH 45103
bone histology 40x	This page has been accessed  times since 29 October 2002.  rvsd 14 October 1991, rvsd 20 Sept. '94, 23 Sept. '96, 14 Sept 99, 4 Oct 01	central canal and osteocytes 400x

See Eroschenko's 9th, pp 47-61
 

    Bone is a remarkable connective tissue derived from hyaline cartilage whose matrix, under the influence of calciferol, has been hardened by the deposition calcium and phosphate to form hydroxyapatite ([Ca₃ (PO₄)₂]·Ca(OH)₂) as the ground substance. Collagen remains the primary fiber in the matrix as it is in hyaline cartilage. Special arrangements are made for supplying blood to this living tissue.  The major supply comes from a vessel housed in the central canal, and cross linkage between central canals are provided by Volkmann's canals. The matrix is maintained by osteocytes, the characteristic cells of bone. Histologically, bone is composed of units termed Haversian systems or osteons in which concentric rings of osteocytes are arranged around a central blood vessel.

Make two illustrations, one an overview of a Haversian system (100x), the second a detailed view of an osteocyte (400x).
 
Use slide 14: Bone, ground (c.s.)
(Because bone cannot be sectioned with a microtome, wafer thin pieces are prepared by grinding down bone.) 

Here is a labeled version.

A. Overview of a Haversian system : (100x) VE:fig 3-17 & 3-19, p 60-61 Haversian system     (osteon) entire complex, functional unit of bone Haversian canal        carries blood vessel through center of osteon lamellae                     "little layer" of matrix between concentric rings of osteocytes lacunae                      "pools" which house osteocytes osteocytes                 "bone cells" which maintain bone Volkmann's canal      feeder cross connecting vessel for blood supply canaliculi                    protoplasmic extensions from osteocytes by which maintenance of bone is performed interstitial lamellae    layers between adjacent Haversian systems

B. An Osteocyte: (400x) VE:fig 3-19, p 61 a smaller illustration showing: a single enlarged osteocyte lacuna chamber in which the osteocyte is held canaliculi "little channels" containing protoplasmic extensions from osteocytes.