| A | B |
|---|
| stress | the reaction of your body to potentially threatening, challenging, or disturbing events |
| organ system | a group of organs that work together to perform a major function |
| cytoplasm | the material in the cell apart from the nucleus; a jelly-like substance that contains the organelles of the cell |
| organ | a structure composed of different kinds of tissue |
| cell membrane | forms the outside boundary of the cell |
| tissue | a group of similar cells that perform the same function |
| nucleus | the control center that directs all of the cell's activities |
| nervous tissue | carries electrical messages back and forth between the brain and other parts of the body |
| muscle tissue | makes parts of the body move |
| connective tissue | provides support for body and connects its parts |
| epithelial tissue | covers the surfaces of the body, inside and out |
