| A | B |
|---|
| cells | the smallest part of a living thing |
| tissue | a group of cells that look alike and do the same job |
| organ | a group of tissues that work together to do the same job |
| system | a group of organs working together to do the same job |
| respiratory system | takes oxygen into your body and releases carbon dioxide |
| trachea | a tube in your throat that air travels down, also called a windpipe |
| diaphragm | a big muscle under your lungs that helps you take air into your lungs |
| lungs | the main organs of your respiratory system |
| digestive system | changes food you eat into a form your body can use and gets rid of the waste products |
| esphagus | a tube that goes from the back of your mouth to your stomach |
| stomach | makes gastric juice and stomach acid, also breaks down large pieces of food |
| small intestine | the organ where blood bessels pick up the nutrients from your food |
| circulatory system | transports oxygen, nutrients, and wastes through the body in the blood |
| skeleton | the framework of bones that holds your body up, gives your body its shape and protects your organs |
| muscles | are joined to bones and move bones by pulling on them |
