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Unformatted text preview: Bone Structure Bone
Dr Sil Wallach Learning Outcomes Learning Describe the components of bone matrix Explain the differences between compact Explain (lamellar) and spongy bone spongy Describe the detailed structure of lamellar bone Explain the terms diaphysis, epiphysis, growth Explain plate, periosteum, endosteum plate, Describe the roles of osteoblasts, osteocytes Describe and osteoclasts and Describe processes of bone growth and Describe remodelling remodelling Functions of bone Functions Support Protection e.g. skull encloses Protection
brain Movement muscles use bones Movement
as levers Mineral storage calcium, Mineral
phosphate Blood cell production in bone Blood
marrow Bone Components Bone 30% organic matrix – flexibility, tensile 30% organic strength strength Collagen fibres Ground substance: proteoglycans, Ground glycoproteins glycoproteins Bone cells 70% inorganic salts – hardness 70% inorganic Hydroxyapatites, calcium phosphates: lie in Hydroxyapatites, and around collagen fibres and Gross anatomy of bone (1) Gross Epiphysis: compact and compact spongy (cancellous) bone bone Diaphysis: compact compact bone collar, bone marrow marrow Gross anatomy of bone (2) Gross Epiphysis Diaphysis Periosteum: dense connective tissue, nerve, dense blood supply; osteogenic cells blood Endosteum: lining layer, osteogenic cells Bone cells Osteoclast: “chomper” Remodelling Osteoblast: “builder” Lay down osteoid Osteocyte “sitter” Microscopic structure of bone (1) Microscopic
Haversian system or osteon lamellae Volkmann’s canal Haversian canal periosteum Microscopic structure of bone (2) Microscopic
Haversian canal lacunae canaliculi Microscopic structure of bone (3) Microscopic Bone development Bone Intramembranous ossification e.g. skull Osteogenic cells switched on and lay down Osteogenic bone in connective tissue “membrane” bone Endochondral ossification e.g. femur Endochondral ossification Osteogenic cells switched on lay down bone Osteogenic on cartilage framework on Bone growth Bone Epiphysial growth Epiphysial plates allow long plates bones to lengthen bones Cartilage cells divide Cartilage replaced Cartilage with bone with Growth plates fuse at Growth age 20 age Remodelling Bone remodelling Bone Occurs during growth. Caused by stress or Occurs immobility immobility Balance between deposition (osteoblasts) and Balance removal (osteoclasts) removal ...
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- Spring '10