Apical surface specialized for secretion. This slide also shows the pancreas - epithelia is glandular, pancreas is an exocrine gland with ducts leading to intestinal lumen 11. Mammalian skeletal muscle in cross section from the adult bone preparation. Haversian system in adult mammalian bone. A blood vessel enters the Haversian canal at the cylinder center.
Bone is alive, it grows, and it remodels.
The Haversion system is evidence of bone remodeling. See PJH for adult bone structure. Haversian systems in a fossilized dinosaur bone . Since in modern vertebrates only warm blooded adults form Haversian systems, their presence in the fossil has been used to argue that dinosaurs were warm blooded. Slides 21 and 23-27 are from the same preparation.