UoB Medicine

Bone Fractures and Healing Covered by periosteum that helps with fracture healing. Contains osteogenic progenitor cells that mature into osteoblasts and therefore increases the thickness.  Two types of bone: CORTICAL and TRABECULAR Cortical bones have a strong outer layer which resists force and weight. It is organised into Haversian systems.                                   Consists of concentric lamallae - rings of calcified matrix.  Contains osteoblasts embedded in lamallae which mature and become osteocytes in lacunae.  Canaliculi - connect lacunae and are used in the movement of nutrients and removal of waste products.  Osteoclasts                                 Has a ruffled border - attaches to the surface of bone and releases lysosomal enzyme...

Healthy Bones and Metabolism Bones consists of: Mineral and Organic part Calcium hydroxyapatite  - provides compressive strength - lack of mineral components of bone results in rubbery and flexible bones = osteomalacia                                            - Collagen (tensile strength) (PG- compressive strength) - Proteoglycans   - provides flexible strength- lack of organic results in brittle bone disease  - Osteocalcin (promotes mineralisation)                                    Ca2+ is produced from:    Bone turnover Resorption from kidneys Diet The regulation of Ca2+ is by:  PTH Vitamin D Calcitonin The amount of Ca2+ is instrumental for the bone density - a measure of the mineral present ...