The musculoskeletal system is made up of the bones of the skeleton, joints that link the bones uesc_09_img0522together and the muscles that enable the body to move. At birth, a baby has around 350 bones, some of which rise together as it grows. Adults usually have 206 bones, though some have extra ribs and others have fewer. The body’s larges bone is the femur in the thigh and its smallest is the tiny stapes in the ear. The muscles and ligaments act with the bones to produce a range of movements, from precision threading of a needle to the most vigorous exercise.
auto-nervous-system2 is a living part of the body that is constantly growing and changing. It has an immense and intricate blood supply, which is why major fractures can cause considerable blood loss. Bone consists of a mesh-like network of collagen, a protein that is the main building block of the body Into this mesh, hone-making cells called osteoblasts deposit calcium and these give bone its hardness and strength. After death the collagen decays, and only the calcium element of the bones remains.
Most hone develops from cartilage (cartilage is the tough, gristly material found at the ends of ribs, in the outer ears and the tip of the nose). When a baby still in the womb, cartilage starts to harden into hone in a process called ossification. As a child grows, the process continues. Bone growth occurs at the ends of the long bones as new cartilage is continually laid down before it goes through the hardening process. The skeleton is not fully formed until around 30 years of age.