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Digestive System: Functions, and Organs Involving the Gastrointestinal Tract

Aug 24, 2023

Digestive System

The digestive system is a network of organs that help in food digestion and nutrient absorption. It comprises your biliary system and gastrointestinal (GI) tract. Your GI tract is made up of a number of interconnected hollow organs that extend from your mouth to your anus. Your biliary system is a network made up of three organs that transport bile and enzymes to your GI tract through your bile ducts.

Gastrointestinal Tract

Your mouth, esophagus, stomach, small intestine, large intestine, and anus are the organs that make up your GI tract, in the order that they are connected.

Biliary system

Your liver, gallbladder, pancreas, and bile ducts are all part of your biliary system.

What functions does the digestive system perform?

Your digestive system is specially designed to do its task of converting food into the nutrients and energy you need to survive. When it's finished, it conveniently bundles your solid waste, or stool, for disposal when you have a bowel movement.

How Important is digestion?

Because your body needs nutrients from the food you consume and the liquids you drink in order to remain healthy and operate normally, digestion is important. Water, vitamins, minerals, proteins, lipids, and carbs are all examples of nutrients. The food and liquids you consume are broken down and their nutrients are absorbed by your digestive system so that you can utilize them for vital functions including energy production, cell growth, and tissue repair.

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What Organs Are Involved In Gastrointestinal Tract?

Your gastrointestinal tract is made up of the primary organs that make up your digestive system. Your mouth, esophagus, stomach, small intestine, large intestine, and anus are among them. Your liver, gallbladder, and pancreas support your GI organs along the process.


The mouth is where the digestive system begins. Actually, digestion starts even before you eat a bite. As you sight and smell that spaghetti dish or warm bread, your salivary glands begin to work. Once you start eating, you chew your meal to break it up into more easily digestible portions. The meal is partially broken down by your saliva so that it may be absorbed and utilized by your body. Your tongue sends food down your throat and into your esophagus when you swallow.


The esophagus collects food from your mouth when you swallow and is situated in your throat close to your trachea (windpipe).

The epiglottis is a little flap that covers your windpipe as you swallow to stop you from choking on food that gets stuck in your windpipe. Food is delivered to your stomach through a process known as peristalsis, which involves a sequence of muscle contractions in the esophagus.

But before food can enter your stomach, a muscle known as the lower esophageal sphincter, which resembles a ring, just relaxes. The sphincter then tightens, preventing the flow of the stomach's contents back into the esophagus. (If it doesn't and the contents flow back into the esophagus, you may have acid reflux or heartburn.)


The stomach, which is a hollow organ or "container," stores food as it is combined with stomach enzymes. These enzymes proceed with the process of turning food into a form that may be consumed. The breakdown process is carried out by powerful enzymes and a strong acid that are secreted by cells in the lining of your stomach. The stomach's contents enter the small intestine after sufficient processing.

Small intestine

The small intestine is a muscular tube that is 22 feet long and made up of three segments: the duodenum, jejunum, and ileum. It uses bile from the liver and enzymes secreted by the pancreas to break down food. In this organ, peristalsis is also active, allowing food to pass through and be mixed with pancreatic and liver juices for digestion.

The first part of the small intestine is called the duodenum. It is principally responsible for the continuous breakdown process. The lower portions of the gut, the jejunum and ileum, are primarily in charge of nutrient absorption into the bloodstream.

The contents go from semi-solid to liquid after passing through the small intestine. Water, bile, enzymes, and mucus are all involved in the shift in consistency.It then travels to the large intestine (colon) once the nutrients have been absorbed and the liquid remaining from the meal has passed through the small intestine.


The pancreas secretes digestive enzymes into the duodenum, where they break down protein, lipids, and carbs. The pancreas produces insulin, which is then directly injected into the bloodstream. Your body's primary hormone for metabolizing sugar is insulin.


Although the liver performs a variety of tasks in the digestive system, its primary duty is to process the nutrients taken up from the small intestine. The small intestine receives bile from the liver, which is released and is crucial for the digestion of fat and several vitamins.

The liver functions as the body's chemical "factory." The numerous chemicals your body requires to function are created from the basic materials ingested by the intestine.

The liver also detoxifies chemicals that may be dangerous. It disintegrates and secretes a variety of medications that may be hazardous to your body.


Bile produced by the liver is stored in the gallbladder, where it is concentrated before being released into the small intestine's duodenum to aid in the absorption and digestion of lipids.


The colon is in charge of processing waste so that bowel movements are simple and quick. The small intestine is joined to the rectum via a 6-foot-long, muscular tube.

The cecum, the ascending (right) colon, the transverse (across) colon, the descending (left), and the sigmoid colon, which links to the rectum, are the components of the colon.

Peristalsis is the mechanism through which stool, or waste from the digestive process, is moved through the colon. Stool initially passes through the colon in a liquid state, but eventually solidifies. Water is eliminated from stools as they go through the colon. The stool is held in the sigmoid (S-shaped) colon until a "mass movement" once or twice a day empties it into the rectum.

Stool usually passes through the colon in around 36 hours. Food particles and germs predominate in the actual stool. These "good" bacteria carry out a number of beneficial processes, including the synthesis of different vitamins, the processing of food and waste materials, and the defense against harmful bacteria.

The descending colon begins the process of elimination (a bowel movement) when it fills up with stool or feces, and empties its contents into the rectum.


The rectum, a straight 8-inch chamber, joins the colon to the anus. Receiving feces from the colon, alerting you that feces need to be evacuated (pooped out), and holding feces until evacuation takes place are the rectum's duties. In the rectum, sensors alert the brain whenever anything (including gas or feces) enters. After then, the brain makes the decision of whether or not to discharge the rectal contents.

The sphincters loosen up and the rectum contracts, expelling the contents if they can. The sphincter contracts and the rectum adjusts if the contents cannot be disposed of, temporarily numbing the sensation.


The digestive system ends with the anus. The pelvic floor muscles and the two anal sphincters (internal and external) make up the 2-inch-long canal. Rectal contents can be felt via the lining of the upper anus. You can determine whether the contents are solid, liquid, or both.

Sphincter muscles that are important in controlling feces are located all around the anus. The stool cannot come out when it is not supposed to because of the angle that the pelvic floor muscle makes between the rectum and the anus. The internal sphincter is always tight, with the exception of when stool enters the rectum.When we are asleep or otherwise ignorant of the presence of stools, this maintains our continent (prevents us from pooping involuntarily).

When we feel the need to relieve ourselves, we rely on our external sphincter to contain the stool until we approach a toilet, where it relaxes to release the contents.

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