Compact Bone

• Study the diagram and image below and then examine the two samples of compact, lamellar bone on this slide. This tissue was not decalcified; it was prepared using a grinding stone rather than a microtome. Cells are not preserved by this method, but the lamellae (both concentric and interstitial), lacunae, cement lines, and canaliculi of osteons (Haversian systems) can be seen.

Study the slide for longitudinal and transverse orientations of osteons. Identify the following:

• Haversian canals
• Volkmann’s canals
• Concentric lamellae
• Interstitial lamellae

Clinical note: Steroid hormones influence the normal balance between bone deposition and absorption. In older individuals this balance is disturbed and there is slow, progressive reduction in bone mass per unit volume. This occurs in both sexes but is accelerated in women after menopause. This often leads to osteoporosis (image at right), in which a reduction in the mass of cortical bone and the number of trabeculae makes the bones fragile.
 

Now let's look at compact and trabecular bone.