Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Session4 Dr. Maria Zahiri ↑ osteoblast ↓ osteoclast osteoblast ↑ osteoclast Vitamin D: increases calcium from gut Parathyroid hormone (PTH): increases blood calcium (some of this comes out of bone) Calcitonin: decreases blood calcium (opposes PTH) Growth hormone & thyroid hormone: modulate bone growth Sex hormones: growth spurt at adolescense and closure of epiphyses Disorders of cartilage and bone Defective collagen Defective endochondral ossification Numerous genetic disorders eg. Osteogenesis imperfecta (brittle bones) – AD (autosomal dominant) eg. Ehlers-Danlos (rubber man) eg. Achondroplasia (short –limb dwarfism) – AD Inadequate calcification (requires calcium and vitamin D) Osteomalacia (soft bones) in adults Rickets in children Disorders of cartilage and bone Defective collagen Osteogenesis imperfecta (OI - brittle bones) congenital bone disorder brittle bones that are prone to fracture defective connective tissue, or without the ability to make it usually deficiency of Type-I collagen Disorders of cartilage and bone Defective collagen Ehlers-Danlos (rubber man) (EDS) is an inherited connective tissue disorder EDS is caused by a defect in the synthesis of collagen, Disorders of cartilage and bone Defective endochondral ossification Achondroplasia (short –limb dwarfism) – AD caused by a change in the DNA for fibroblast growth factor receptor 3 (FGFR3), which causes an abnormality of cartilage formation Disorders of cartilage and bone Inadequate calcification (requires calcium and vitamin D) Osteomalacia (soft bones) in adults Rickets in children is the softening of the bones caused by defective bone mineralization secondary to inadequate amounts of available phosphorus and calcium, or because of overactive resorption of calcium from the bone as a result of hyperparathyroidism (which causes hypercalcemia, Pagets disease – excessive turnover, abnormal bone Osteosarcoma – bone cancer, affecting children primarily Osteoporosis – usually age related, esp. females Low bone mass and increased fractures Resorption outpaces bone deposition Normal bone Osteoporotic bone اشید در پناه خداوند باشبد