A

David

Darling

endoskeleton

The endoskeleton is a supporting system of bones and cartilage inside the body of an animal. All vertebrates have an endoskeleton. It supports the body, and surrounds and protects internal organs. It also provides attachment points for muscles in order to facilitate movement. Sponges have a type of endoskeleton consisting of a network of rigid or semi-rigid spicules. See also exoskeleton.