The skull and crossbones flying from a pirate ship have long been a symbol of death. Therefore, you might think that bones are dead structures made of rocklike material. This isn't true. The bones in your body are very much alive!

Bones are living structures with 5 functions:

• protect internal organs
• support the body
• make blood cells
• store minerals
• provide for muscle attachment

A point where two or more bones connect is called a joint. There are two different types of joints in the body:

• Movable joints (like ball-and-socket, hinge, gliding and pivot joints)
• Immovable joints (like the bones of the skull and pelvis) which allow little or no movement