Bone Repair PDF

1-Types of Bone Cells: -Osteocytes Mature bone cells -Osteoblasts Bone-forming cells -Osteoclasts Bone-destroying cells and break down bone matrix for remodeling ----------------------------------------------------------------------------------------------------...

1-Types of Bone Cells: -Osteocytes Mature bone cells -Osteoblasts Bone-forming cells -Osteoclasts Bone-destroying cells and break down bone matrix for remodeling --------------------------------------------------------------------------------------------------------------------- 2- Bone Development: -In embryos , bone development begins in second month of development. (ossification) Connective tissue cartilage bone cavity bone cell osteoblast n Bone formation cartilage ‫ عباره عن‬Connective tissue ‫في بداية تكوين الجنيين بيبقي ال‬ \ bone cavity ‫انه يموت ويسيب فراغات مكانه الي هي‬ cartilage ‫وبعدين بيبدأ ال‬ ‫ وبيكون مع الدم الي رايح لها‬Bone cavity ‫ لل‬Blood supply ‫تدريجيا بيبدأ يحصل‬, ‫الي بتعمل علي تكوين العظام‬ osteoblast ‫ الي بتكون‬bone cell ‫بعض من‬ ossification ‫وتبدأ تعمل‬ --------------------------------------------------------------------------------------------------------------------- 4-Bone Growth: -Epiphyseal plates allow for growth of long bone during childhood -Bone replaces cartilage Epiphyseal plates: growth linear Appositional growth: growth thickness 4-Bone Maintenance & Repair: A. Bone remodeling: 1.Life long process 2. Local areas of bone and rebuilt 3. Repairs microdamage caused by normal wear and tear Bones are remodeled continually in response to changes in two factors: 1-Calcium Levels in the blood 2-The pull of gravity and muscles on the skeleton urine Calcium Deposition on bone Bone density.‫ يا اما انه ينزل في البول او يترسب في العظام ويزود كثافتها‬, ‫في حالة لو الكالسيوم عالي في الدم قدامه اختيارين‬ Release calcium Calcium Parathyroid hormone Osteoclasts Bone-destroying cells ‫ تكسر بعض خاليا العظم عشان‬Osteoclasts ‫في حاله نقص الكالسيوم بيتم افراز الباراثورمون الي بيخلي ال‬.‫ترفع نسبة الكالسيوم‬ --------------------------------------------------------------------------------------------------------------------- 5-Hormonal Regulation of Bone: During infancy and childhood, epiphyseal plate activity is stimulated by growth hormone During puberty, testosterone and estrogens Later induce epiphyseal plate closure, ending longitudinal bone growth. --------------------------------------------------------------------------------------------------------------------- 6-Bone Fractures: 1-Closed (simple) fracture: break that does not penetrate the skin. 2-Open (compound) fracture: broken bone penetrates through the skin. 3- Displaced: the bone snaps into two or more parts and moves so that the two ends are NOT lined up straight. 4- Non-displaced: the bone cracks either part of all of the way through, but does move and maintains its proper alignment. ‫الشرخ‬ 5-Greenstick: Does not break completely and most common in children. Transverse fracture: Broken straight across the bone Spiral or Oblique: twisting movements ‫هشاشة عظام‬ Crush fractures: Fracture in cancellous bone: result of compression (osteoporosis) Impacted fracture: Bone fragments are impacted into each other. Comminuted fracture: Two or more bone pieces --------------------------------------------------------------------------------------------------------------------- 7- Bone Repair: 1-Hematoma formation: swelling ,pain ,inflammation and blood clotting. Fibroblast and chondroblast ‫بيبجي علي مكان الكسر نوعين من الخاليا‬Clotting ‫لما بيحصل‬ 2-Fibroblast fibrous Fibrocartilage callus chondroblast cartilage 3- Fibrocartilage callus calsification bony callus ‫عبارة عن نتوءات عظميه‬ 4-Bone remodeling: Bony callus is remodeled to form a permanent patch. Bone callus begins 3-4 weeks after injury, and continues until firm union is formed 2-3 months later