佝偻病（英文课件）.pptVIP

Rickets of Vitamin D Deficiency The Second Affiliated Hospital of Shantou University Medical College  Ma Lian  Review Rickets：signifying a failure in inernalization of growing bone or osteoid tissue. Failure of mature bone to mineralize is called osteomalacia. Etiology Inadequate direct exposure to ultraviolet rays in sunlight Inadequate intake of vitD (diet may contain little vitD) Growth drug Disease:hepatic and renal lesions、celiac disease、steatorrhea or cystic fibrosis Or both About Vitamin-D Two forms : vitD2 /vitD3 vitD2 :most as irradiated ergosterol,largely replaced the fish liver oils as source vitD3 :available in human skin as 7-dehydrocholesterol. both are hydroxylated in the liver to 25－ (OH)2D in the renal to 1. 25－(OH)2D: facilitate calcium and phosphorus absorpted Pathology the epiphyseal plate of metaphysis is well demonstrated. The cartilage cell is orderly The calcified matrix forms the epiphyseal plate is regular The degenerating cartilage, islands of capillaries, osteoblasts, and unmineralized osteoid compose of broad , irregular, rachitic imtermediate zone Chemical pathology can be conceptualized to be the body’s attempt to maintain normal serum calcium levels. When calcium is less?parathormone is secreted?increase the calcium and phosphorus concentration Alkaline phosphatase (ALP). (normal level ≦200IU/dL) can be 500UI/dL. But may be normal in infants who have rickets and who are protein or zinc depleted. aminoaciduria, a decrease of citrate ,and its increased urinary excretion, decreased ability of the kidneys to make an acid urine, phosphaturia, and occasionally ,mellituria. The parathyroid glands hypertrophy Clinical manifestations Early signs: Increased sweating, particularly around the head ,which result in the occipital bone bare Clinical manifestations Advanced rickets: Head: early signs is craniotabes, Like a derby hat or ping pong ball . Thorax: rachitic ros