Human Bones

   Bones are an important part of the human superstructure. They keep the body upright and allow bends in joints and sockets. There are three main parts to a bone: the compact bone, the spongy bone, and the medullary cavity, (as seen in the picture to the right).

        Bones are made up of collagen and minerals. The collagen is the flexible part of the bone made up of chemicals called proteins, the minerals are the hard part of the bone and are made up of chemicals called calcium.
         Both the compact bone and the spongy bone are made of the same substance (collagen and, the only difference is the substances are packed differently. In the compact bone the substances are packed hard to make a hard, tough substance; where as the spongy bone there are little holes throughout the hard bone, which gives it a spongy look, although it is quite hard giving support without much weight.

          The medullary cavity consists of red bone marrow, yellow bone marrow, and blood vessels. The red bone marrow produces the cells in your blood, and the yellow bone marrow is composed of fats being stored in your body.

            The bone is then covered by a substance called periosteum that is the white part of the bone that you see. This part of the bone contains blood vessels for nutrition in your bones. It also contains nerves to send signals to your brain if it gets damaged.