MEDI111 Lecture Notes - Lecture 2: Ossification, Bone Marrow, Hydroxylapatite
6 Aug 2018
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Document Summary
Functions of bone: support soft tissue and organs, protection, movement joint, mineral and fat storage (calcium, fat, hemopolesis blood cell formation in red marrow. Bone cells: osteocytes maintain bone, osteoblasts create bone, osteoclasts dissolve bone, osteoprogenitor cells create osteoblasts. Bone matrix (inorganic) hydroxyapatite crystals concrete (organic) collagen fibres steel reinforcement. The osteon: functional unit of compact bone. Development of bone: ossification development of bone (8 weeks in embryo, endochondral ossification cartilage used as model for long bone formation. Intramembranous ossification flat bones of skull are formed (+ clavicle) Bone repair: fractures are breaks, during youth, most fractures occur from trauma. In old age, most result from weakness of bone due to thinning. Infancy and childhood: growth hormone stimulates epiphyseal plate activity, puberty, testosterone protein synthesis, bone growth, estrogen bone growth, fat deposition (thighs and hips) Bone change in size and shape: 3 processes. Growth at growth plates cartilage proliferates and undergoes calcification.
