The Skeletal System

The skeletal system forms the body’s supporting framework, giving it structure and shape through a network of bones and connective tissues. It protects internal organs, works with muscles to enable movement, and stores minerals such as calcium and phosphorus. The adult human skeleton typically contains 206 bones, linked by joints and ligaments. These bones belong to two main divisions: the axial skeleton, which consists of the skull, spine, and rib cage, and the appendicular skeleton, which includes the arms, legs, shoulder girdle, and pelvic girdle.

Bone is living tissue that continually renews itself through a process known as remodeling, in which old bone is broken down and replaced with new bone. This ongoing renewal helps bones respond to growth and changes in physical demands, including exercise. Other connective tissues support the skeleton’s function. Cartilage cushions joints and absorbs impact, tendons attach muscles to bones, and ligaments connect bones to one another. The skeletal system also contributes to blood cell production: marrow inside certain bones produces red blood cells, white blood cells, and platelets.