The skeletal system is composed of a network of hard and soft tissues including bone, cartilage, ligaments, and tendons. Together, these tissues form an overall framework, thus giving the body its characteristic shape and providing structural support. Additionally, the skeletal system protects internal organs and facilitates movement by providing attachment sites for muscles. Other functions of the skeletal system include a storage facility for minerals such as calcium, formation of blood cells, and an energy reserve of lipids.

The bones of the skeletal system can be classified according to their shape and location. The types of bones categorized by shape--long, short, flat, and irregular--also provide evidence of their function. Long bones consist of an elongated shaft called the diaphysis. Each end of the diaphysis is an expanded portion of the shaft and is called an epiphysis. Examples of long bones include the...