KINESIOL 1C03 Lecture Notes - Lecture 13: Prostaglandin E2, Piezoelectricity, Premature Ovarian Failure
19 Apr 2016
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Document Summary
Mechanical support and protection: protects organs and supports muscles. Reservoir for minerals: contains 99% of calcium. A dynamic tissue that undergoes remodeling: continuous cycles of formation and resorption. Dependent on 2 specific cells: osteoblasts formation, osteoclasts resorption. Activation phase: osteoclasts become activated, breaks down bone. Formation phase: osteoblasts become activated, rebuilds bone, takes longer. Resting phase: cells on bone become dormant, already remodeled. Youth: bone formation > bone resorption. Young adulthood: bone formation = bone resorption. After 3rd decade (30s: bone formation < bone resorption. Primarily in the shafts of long bone: located on the outside of all bones. 75-80% of total skeleton mass: 33% of total bone surface. Primarily in spine, pelvis and long bone ends: higher surface to volume ratio. Accounts for less of total bone mass: but has more total bone surface. Loses bone mineral sooner and faster: more surface means more cells. Decreased bone mass: due to aging.
