Periosteum

The periosteum is made up of a thin, dense membrane that contains nerves and blood vessels.

Compact Bone

The Compact Bone is smooth and very hard. This is the part of the bone that is shown when you look at a skeleton.

Cancellous Layers

The Cancellous Layers looks like a sponge. This part of the bone is not quite as hard as compact bone, but it is still very strong.

Bone Marrow

The bone marrow is a sort of thick jelly that makes blood cells.