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Duke Orthopaedics
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Wheeless' Textbook of Orthopaedics

Osteoblasts



- Discussion:
    - see: osteocytes and osteoclasts
    - arise from marrow stroma cells, and are found on the surfaces where bone is being formed;
    - may require bone morphogenic proteins for induction into osteoblasts;
    - generally regarded as bone forming cells;
           - most obvious function is to synthesize osteoid;
           - in certain situations, they initiate bone resorption;
           - osteoblasts synthesize collagen and to control its subsequent mineralization;
    - w/ rapid osteogenesis, cells are usually quite plump & cuboidal.
    - when mature bone is being formed slowly, lining osteoblasts tend to be thin, flat, and elongated;
    - osteoblasts have cytoplasmic processes that extend to adjacent osteoblasts & into bone substance by way of canaliculi to join processes of osteocytes;
    - both cytoplasm & nucleus of osteoblasts contain enzyme alkaline phosphatase, which can be used as a marker for osteoblast activity;
    - bone formation is a two-step process that involves matrix formation & mineralization;
    - receptors:
          - estrogen
          - parathyroid hormone
          - vit D

- Histology:
    - they vary in size and shape, most being 20-30 micrometers in diameter;
    - they are usually closely arranged in a dense single layer of cells covering bone surface, but where bone formation is active, there may be several layers of cells



The effect of glucocorticoids on osteoblast function. The effect of corticosterone on osteoblast expression of beta 1 integrins.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, June 1, 2012 8:43 am