The food you eat takes an incredible journey through your body, from vị trí cao nhất (your mouth) khổng lồ bottom (your anus). Along the way the beneficial parts of your food are absorbed, giving you energy & nutrients. Here’s a step-by-step trương mục of the digestive system’s workings.
Structure of the Digestive System

What is the digestive system?

Your digestive system is made up of the gastrointestinal (GI) tract & your liver, pancreas và gallbladder. The GI tract is a series of hollow organs that are connected to each other from your mouth to lớn your anus. The organs that trang điểm your GI tract, in the order that they are connected, include your mouth, esophagus, stomach, small intestine, large intestine và anus.

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What does the digestive system do?

Your digestive system is uniquely constructed to vì its job of turning your food into the nutrients & energy you need khổng lồ survive. & when it’s done with that, it handily packages your solid waste, or stool, for disposal when you have a bowel movement.

Why is digestion important?

Digestion is important because your toàn thân needs nutrients from the food you eat & the liquids you drink in order to stay healthy and function properly. Nutrients include carbohydrates, proteins, fats, vitamins, minerals and water. Your digestive system breaks down và absorbs nutrients from the food and liquids you consume to lớn use for important things like energy, growth and repairing cells.

What organs hóa trang the digestive system?

The main organs that make up the digestive system (in order of their function) are the mouth, esophagus, stomach, small intestine, large intestine, rectum & anus. Helping them along the way are the pancreas, gall bladder & liver.

Here’s how these organs work together in your digestive system.



The mouth is the beginning of the digestive tract. In fact, digestion starts before you even take a bite. Your salivary glands get active as you see và smell that pasta dish or warm bread. After you start eating, you chew your food into pieces that are more easily digested. Your saliva mixes with the food khổng lồ begin lớn break it down into a khung your body can absorb & use. When you swallow, your tongue passes the food into your throat & into your esophagus.


Located in your throat near your trachea (windpipe), the esophagus receives food from your mouth when you swallow. The epiglottis is a small flap that folds over your windpipe as you swallow lớn prevent you from choking (when food goes into your windpipe). A series of muscular contractions within the esophagus called peristalsis delivers food to lớn your stomach.

But first a ring-like muscle at the bottom of your esophagus called the lower esophageal sphincter has to relax to let the food in. The sphincter then contracts và prevents the contents of the stomach from flowing back into the esophagus. (When it doesn’t and these contents flow back into the esophagus, you may experience acid reflux or heartburn.)


The stomach is a hollow organ, or "container," that holds food while it is being mixed with stomach enzymes. These enzymes continue the process of breaking down food into a usable form. Cells in the lining of your stomach secrete a strong acid và powerful enzymes that are responsible for the breakdown process. When the contents of the stomach are processed enough, they’re released into the small intestine.

Small intestine

Made up of three segments — the duodenum, jejunum, and ileum — the small intestine is a 22-foot long muscular tube that breaks down food using enzymes released by the pancreas & bile from the liver. Peristalsis also works in this organ, moving food through and mixing it with digestive juices from the pancreas & liver.

The duodenum is the first segment of the small intestine. It’s largely responsible for the continuous breaking-down process. The jejunum và ileum lower in the intestine are mainly responsible for the absorption of nutrients into the bloodstream.

Contents of the small intestine start out semi-solid and end in a liquid size after passing through the organ. Water, bile, enzymes and mucus contribute to the change in consistency. Once the nutrients have been absorbed và the leftover-food residue liquid has passed through the small intestine, it then moves on to the large intestine (colon).


The pancreas secretes digestive enzymes into the duodenum that break down protein, fats & carbohydrates. The pancreas also makes insulin, passing it directly into the bloodstream. Insulin is the chief hormone in your body toàn thân for metabolizing sugar.


The liver has many functions, but its main job within the digestive system is to lớn process the nutrients absorbed from the small intestine. Bile from the liver secreted into the small intestine also plays an important role in digesting fat & some vitamins.

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The liver is your body's chemical "factory." It takes the raw materials absorbed by the intestine & makes all the various chemicals your body toàn thân needs to lớn function.

The liver also detoxifies potentially harmful chemicals. It breaks down & secretes many drugs that can be toxic lớn your body.


The gallbladder stores và concentrates bile from the liver, và then releases it into the duodenum in the small intestine lớn help absorb và digest fats.


The colon is responsible for processing waste so that emptying your bowels is easy và convenient. It’s a 6-foot long muscular tube that connects the small intestine lớn the rectum.

The colon is made up of the cecum, the ascending (right) colon, the transverse (across) colon, the descending (left) colon, & the sigmoid colon, which connects to the rectum.

Stool, or waste left over from the digestive process, is passed through the colon by means of peristalsis, first in a liquid state và ultimately in a solid form. As stool passes through the colon, water is removed. Stool is stored in the sigmoid (S-shaped) colon until a "mass movement" empties it into the rectum once or twice a day.

It normally takes about 36 hours for stool to get through the colon. The stool itself is mostly food debris and bacteria. These “good” bacteria perform several useful functions, such as synthesizing various vitamins, processing waste products và food particles and protecting against harmful bacteria. When the descending colon becomes full of stool, or feces, it empties its contents into the rectum to lớn begin the process of elimination (a bowel movement).


The rectum is a straight, 8-inch chamber that connects the colon to lớn the anus. The rectum's job is khổng lồ receive stool from the colon, let you know that there is stool khổng lồ be evacuated (pooped out) & to hold the stool until evacuation happens. When anything (gas or stool) comes into the rectum, sensors send a message to lớn the brain. The brain then decides if the rectal contents can be released or not.

If they can, the sphincters relax and the rectum contracts, disposing its contents. If the contents cannot be disposed, the sphincter contracts and the rectum accommodates so that the sensation temporarily goes away.


The anus is the last part of the digestive tract. It is a 2-inch long canal consisting of the pelvic floor muscles và the two anal sphincters (internal & external). The lining of the upper anus is able lớn detect rectal contents. It lets you know whether the contents are liquid, gas or solid.

The anus is surrounded by sphincter muscles that are important in allowing control of stool. The pelvic floor muscle creates an angle between the rectum & the anus that stops stool from coming out when it’s not supposed to. The internal sphincter is always tight, except when stool enters the rectum. This keeps us continent (prevents us from pooping involuntarily) when we are asleep or otherwise unaware of the presence of stool.

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When we get an urge to go to lớn the bathroom, we rely on our external sphincter lớn hold the stool until reaching a toilet, where it then relaxes to release the contents.