The meaning of the internal skeleton.

The internal skeleton is the one hidden behind the skin and muscles. It is essential for the life of many animals. It provides support for muscles and organs. It also enables movement and protects important internal organs. For example: the skull protects the brain, the ribs protect the heart and lungs, and so on. There is also an external skeleton. It is found in some animals. Man has only an internal skeleton. The teeth should not be confused with the external skeleton. Although they are outside the skin and muscles, the teeth have nothing to do with the skeleton.