| Term | Definition |
| epidermis | outer, thinest layer of your skin |
| Melanin | pigment that protects your skin and gives it color |
| dermis | the layer of cells directly below the epidermis |
| muscle | organ that can relax, contract and provide teh force to move your body parts |
| voluntary muscles | muscles you are able to control |
| skeleton muscles | the muscles that move bones |
| tendons | more common than other muscle types; attached to the bone by thick bands of tissues |
| involuntary muscles | muscles you can't control consciously |
| cardiac muscles | only found in the heart; contracts 70 times a minute |
| striated | appear striped |
| smooth muscles | Non striated; found in your intestines, bladder, blood vessels, & internal organs |
| sketeton system | all the bones in your body |
| cartilage | the ends of bones are covered with a slippery, smooth, thick layer of tissue |
| Joint | a place where two or more bones come together |
| ligament | bones are held in a place at these joints by a tough band of tissue |
| periosteum | living bones surface is covered with a slippery, smooth, thick layer of tissue |