The skeletal system provides structure, protection, movement, and hematopoiesis in the body. It is composed of bones and cartilage connected by ligaments at joints. Bones are living tissues composed mainly of calcium and phosphorus. They contain bone marrow which produces red and white blood cells. The skeletal system interacts with other systems like the muscular and circulatory systems to enable movement and protection of organs. Diseases like osteosarcoma can affect the bones.

1. The Skeletal System By Patricia Rojas and Carly Schwartz Image from:http://homes.bio.psu.edu/people/faculty/strauss/anatomy/skel/skeletal.htm