Your skeleton is the strong internal structure that supports
your body. The skeleton is about 20% of your body weight.
The human skeleton has 206 bones, including three in each
ear and one in the neck attached to the tongue. Bone
contains the element calcium.
Did you have more or fewer bones than when you were
A joint is where bones connect. Some joints are rigid, while
others allow motion.
Hips have a ball-and-socket joint, allowing movement in all directions. Knees use a hinge joint, with movement in one plane.
Joints, severely damaged by injury or arthritis, might need to be replaced. Artificial joints are called orthopedics. Warsaw, Indiana, just west of Fort Wayne, is a world leader in developing orthopedics.
Do you know anyone with an artificial joint?