Parts of the Digestive System



Parts of the Digestive System

The digestive system consists of the nose, mouth, esophagus, stomach, small intestine, pancreas, liver, gall bladder, and colon (large intestine). Each of these highly specialized organs has its own job to do. Working together, they beak down food so that it can be used by the body. more


The nose is included here because our sense of smell cues our brains and other organs to get ready for the food that is soon to be eaten. Powerful chemicals are released even before food touches our mouths! To a certain extent, our eyes do the same thing.


The mouth is far more complex than one might think. Digestion truly starts when food touches the mouth. Chewing mechanically breaks food down, while saliva begins the chemical process of digestion.

Digestion after swallowing

After swallowing, food travels through the esophagus where peristalsis (muscular contractions move the food to the stomach. There food is mixed with enzymes that further break down the food. When the food is broken down enough, it is no longer recognizable as food, but has great value, as it is ready to be further processed and absorbed in the small intestine.

The Small Intestine

The small intestine is over twenty feet long and consists of three segments- the duodenum, jejunum, and ileum. By the action called peristalsis and the addition of enzymes from the liver and pancreas, food is broken down until it is ready to be absorbed. The duodenum does most of the breaking down, while the ileum and jejunum absorb the nutrients that will be used by the body.

The Liver

The liver is a multi-purpose organ, but its function during digestion is to process the nutrients in the small intestine by secreting bile into the small intestine. The liver also helps with the digestion of fats and takes nutrients and turns them into important chemicals needed for other parts of the body to function.

Gall Bladder

The gallbladder stores bile and sends it to the duodenum when needed to help break down and absorb fats.

The pancreas also secretes enzymes into the duodenum where proteins, fats and carbohydrates are broken down. The pancreas also makes and releases insulin which metabolizes sugar in the blood stream.

The Colon

The colon, or large intestine, is about six feet long. It connects the small intestine to the rectum and processes waste, or what’s left over after digestion. Wastes enter the colon in liquid form consisting of bacteria and food debris. Water is extracted and waste becomes more concentrated, forming a stool, or what we call feces. The colon empties the stool into the rectum when it becomes full and goes from the rectum to the anus and is expelled. More GI Tract Organs

Parts of the Digestive System