| A | B |
|---|
| epidermis | Outer layer of tissue in humans and animals. |
| dermis | the thick inner layer of the skin |
| subcutaneous layer | Layer of fat and connective tissues below the dermis of the skin. |
| melanin | A dark brown or black pigment. |
| callus | An area of skin with a thickened epidermis |
| blister | a water filled swelling of the epidermis of the skin |
| bone marrow | a soft tissue that produces blood cells in the marrow of long bones and spongy spaces |
| ligament | A band of connective tissue that holds the bones of a joint in place. |
| tendon | the connective tissue that attaches muscle to bone. |
| bone | strong supporting structure of vertebrates. |
| osteon | A microscopic unit of a bone consisting of a blood vessel and layers of hard nonliving material around it. |
| cartilage | A flexible supporting tissue that makes up part or all of some animals skeletons. |
| joint | place where two or more bones meet. |
| voluntary muscle | A muscle that can be controlled at will. |
| skeletal muscle | Muscle tissue that attaches to and moves the skeleton. |
| striated muscle | muscle tissue that displays a pattern of light and dark bands |
| involuntary muscle | a muscle controlled automatically by the brain without conscious effort. |
| smooth muscle | Muscle tissue that lacks striations; forms walls of many internal organs. |
| cardiac muscle | a kind of striated involuntary muscle that is found in the heart. |
