GERON255 Lecture Notes - Lecture 22: Haversian Canal, Geron Corporation, Osteoblast
19 Apr 2016
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Document Summary
Microscope structure or a cross section of a long bone: Compact bone: structural unit called a haversian system (osteon, haversian unit contains: Tiny canals called canaliculi interconnect lacunae (cid:3) 3 major types of cells in bone tissue. Osteoblasts: synthesize collagen fibres and coat them with calcium and phosphorus, builds bones!!! Osteocytes: found in lacunae, inactive trapped cells but can be re-stimulated to osteoblasts if broken bone. Osteoclasts: breakdown and mineralize bone, reabsorb bone in response to decreased level of calcium in blood controlled by hormones (building or breakdown of) (cid:3) (cid:3) Stress: bones get stronger when subjected to stress because of increase of mineralized bone. By increasing amount of collage fibres and coating them with inorganic salts (by the osteoblasts: as we age we decrease exercise. Nutrition: balanced diet (need high calcium in blood to build bone, bone formation we need vitamin d to take calcium across intestine wall to blood stream, elderly people have poor diets, diminished appetites.
