| A | B |
|---|
| anatomist | A person who studies anatomy--the physical makeup and structure of the body |
| antagonistic Muscles | Muscles that pull in opposite directions, with one member of the pair pulling the bone one way and the other pulling it back. |
| bone | A strong body part. There are 206 of these in an adult skeleton . These are fairly rigid but also slightly flexible. |
| cartilage | A tough, rubbery substance. It lines the ends of bones where they meet in a joint. It also forms parts in the nose and the larynx. |
| cells | The microscopic units that make up all living things, including the human body. The body has more than 100 million million of these. |
| genes | Units of inheritance passed from parents to their offspring. They are the plans for each feature of the body, such as bone shape, intestinal structure, and skin color. |
| joint | The part of the body where two bones meet. |
| ligaments | Tough, elastic straplike parts that attach bones together at a joint, so that they do not come apart. |
| marrow | The jellylike substance inside certain bones. It makes new cells for the blood. |
| muscle | A body part specialized to contract (get shorter). |
| nerve | A long, thin body part that is specialized to carry messages around the body in the form of tiny electrical signals. |
| organ | A major structural part of the body that carries out an important role. A heart is an example. |
| osteo- | To do with bones. |
| proteins | The body's main construction substances. They make up skin, muscles, bones, and many other parts. |
| skeleton | The supporting framework of the body. |
| skin | The organ of touch and the body's outer covering. |
| system | A group of organs of other parts that carries out one major role. |
| tendon | The strong ropelike part of a muscle, where it narrows toward its end and is attached to a bone. Also called a sinew. |
| hinge joint | A joint that moves like the hinge on a door. The knee is a hinge joint. |
| x-rays | Invisible waves that can pass through most of the body, except for hard parts such as the bones. |
