![]() ![]() Type I collagen is initially synthesized in the rough endoplasmic reticulum (RER) as a precursor molecule (type I procollagen) that combines two proα1(I) and one proα2(I) peptide chains (coded by COL1A1 and COL1A2, respectively) in a triple helix. ![]() However, the surface-to-volume ratio of trabecular bone is very much higher than that of cortical bone and it is metabolically much more active.Īt a microscopic level, bone consists of matrix (~35% by volume), mineral (~60%) and cells ( 300 000 Da) with a trimeric helical structure. Some 80% of the weight of an adult human skeleton consists of cortical bone. The diaphysis of the long bone consists mainly of cortical bone, whereas the metaphysis and epiphysis have a greater quantity of trabecular bone, enclosed within a thin cortical envelope. The elements of bone can be packed together without intervening marrow spaces to form cortical or compact bone, or they can form an interlacing meshwork of trabeculae referred to as cancellous or trabecular bone. On sectioning a long bone, two patterns of organization of bone tissue are found. The transitional zone between the diaphysis and the epiphysis is termed the metaphysis. A long bone consists of a shaft (diaphysis) broadening at either end into an epiphysis. Flat bones result from intramembranous ossification long bones predominantly from endochondral ossification. skull, scapula, mandible, ilium) or long (e.g. The anatomist classifies bones as being either flat (e.g. ![]() Metabolic bone diseases can affect both these functions. It also has an important secondary role in mineral homoeostasis, functioning as a reservoir for calcium ions in particular. The principal role of the skeleton is a structural one, maintaining body shape, providing protection for internal organs and, together with the neuromuscular system, making locomotion possible. Defective osteoblast function and osteomalaciaĬHRONIC KIDNEY DISEASE – MINERAL AND BONE DISORDERīONE DISEASE IN PRIMARY HYPERPARATHYROIDISMĬlinical, biochemical and histological featuresīONE TURNOVER AND BONE DISEASE IN CHILDREN ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |