When you put food in your mouth, our teeth grind it up with saliva. Saliva is also known as spit. Saliva helps our body break down food. After it’s small enough you swallow. When you swallow your food it goes down a tube called the esophagus. The esophagus muscles push the food down toward the stomach. The sphincter muscle lets the food into your muscle. There is a lot of hydrochloric acid in your stomach. This also helps to break down food into small pieces. Saliva mixed with hydrochloric acid makes gastric juices. Gastric juices are the thing that breaks down the food the most. The stomach’s muscles break down the food with help from gastric juices. When the stomach is done the food is a mushy liquid called chyme.

The stomach’s sphincter muscle lets the chyme into the small intestine. The small intestine has tons of little 1 cm things called villi covering the walls. Villi suck in nutrients and put it into the blood stream. When the chyme comes out of the small intestine and goes into the large intestine it is full of special juices. The walls of the large intestine suck in these juices and other moisture, and sends it into the blood stream, and back to where it is needed. The chyme now looks like excrement (poo). It is stored in the rectum (until you use the toilet). When you are ready the sphincter muscle lets it out of the rectum, out through the anus, and into the toilet.