The Skeletal System Essay

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The skeletal system includes the osseous tissues of the body and the connective tissues that stabilize or interconnect the individual bones. The bone is a dynamic tissue. Throughout the lifespan, bone adjusts to the physiologic and mechanical demands placed on it by the processes of growth and remodeling. Bone serves the organism at multiple levels: As a system, bones permit the organism to locomote effectively and to maintain posture by bearing loads without deformation, by providing rigid attachment sites for muscles and acting as a system of levers to amplify small movements. As an organ, bones protect the viscera and house the hemopoietic tissue (red marrow). As a tissue, bones serve as a reservoir of readily mobilizable calcium, an…show more content…
The calcium salts of bone represent a valuable mineral reserve that maintains normal concentrations of calcium and phosphate ions in body fluids. In addition, fat cells within marrow cavities store lipids that represent an important energy reserve. The bones of the skeleton function as levers that direct and modify the forces generated by skeletal muscles. The movements produced range from the delicate motion of a fingertip to powerful changes in the position of the entire body. Osseous tissue contains specialized cells, cell products, and a fluid matrix. The distinctive solid, stony nature of bone results from the deposition of calcium salts within the matrix. Crystals of calcium phosphate account for almost two-thirds of the weight of the bone. The majority of bone mineral occurs in the form of hydroxylated calcium phosphate crystals
(Ca 10 [PO 4 ] 6 [OH]2 ) referred to as hydroxyapatite. The remaining third is dominated by collagen fibers, with osteocytes and proteoglycans contributing only around 2 percent.
Calcium phosphate crystals are very strong, but inflexible. They can withstand compression, but the crystals are likely to shatter when exposed to bending, twisting, or sudden impacts. Collagen fibers are extremely tough, but quite flexible. They can easily tolerate stretching, twisting, and bending, but when compressed they simply bend out of the way. In bone, the collagen fibers

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