The skeleton has four main functions: providing shape, enabling movement, protecting organs, and producing blood cells. It gives the body its shape and allows for movement through joints and muscle attachment. The skeleton protects vital organs like the heart, lungs, and brain. Bone marrow inside bones produces red and white blood cells. There are over 200 bones in the adult body that can be categorized as flat, irregular, or long bones depending on their shape.

1. The Skeleton and Joints What the skeleton does

15. Joints of the Human Body