LYCOS RETRIEVER 
Bones: Cartilage
built 630 days ago
The long bones are formed by a combination of endochondral and intramembranous bone formation. The initial bone collar at the primary center is made by intramembranous ossification. halfway between the ends of the cartilage model, the osteogenic capacity of cells of the perichondrium is activated leading to development of the bone collar. Subsequently, blood vessels penetrate into the cartilage model leading to endochondral ossification. Growth in width of the diaphysis of large bones occurs in a manner similar to that of the "membrane" bones (e.g. calvaria).
Source:
The bones of kids and young teens are smaller than those of adults and contain "growing zones" called growth plates. These plates consist of columns of multiplying cartilage cells that grow in length, and then change into hard, mineralized bone. These growth plates are easy to spot on an X-ray. Because girls mature at an earlier age than boys, their growth plates change into hard bone at an earlier age.
Source:
Insulin-like growth factor-1 (IGF-1) is the direct mediator of growth hormone's effect on statural growth and must be present in order for children's bones, cartilage, and organs to grow normally. Primary IGFD is a growth hormone-resistant state characterized by abnormally low blood IGF-1 levels in the presence of normal or elevated endogenous growth hormone.
Source:
As strong as bones are, they can break. Muscles can weaken, and joints (as well as tendons, ligaments, and cartilage) can be damaged by injury or disease. The following are problems that can affect the bones, muscles, and joints in kids and teens:
Source:
MORE ABOUT
Cartilage