Anatomy And Physiology

How the Digestive System Works

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"How the Digestive System Works"
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Our bodies are very unique and smart. Your body is your protector and knows how to break down all the food you eat through the process of digestion. The body is a system where everything just falls in place and know hows to retrieve the most nutrients out of every morsel of food you put in your mouth. It is truly is an amazing system, and when in good working order keeps you healthy, strong and helps to attribute to a long and healthy life.

In order to understand how the digestive process works, lets start with what happens when you put food in your mouth. Digestion starts in your mouth, this is where chewing takes place and is known as mastication in medical terms. At the same time salivation is occuring and then swallowing takes place. The mouth, pharynx, esophagus, stomach and your small and large intestines are known as your GI (gastrointestinal system) system and are all part of what is known as the alimentary canal. The alimentary canal is a hollow muscular organ that begins with your mouth and extends all the way to the anus.

When an individual swallows a piece of food, a sphincter in your upper esophagus relaxes and allows food to enter the esophagus. The esophagus has a nerve that activates a process known as peristalsis. Peristalsis is the process that moves food down your esophagus to the stomach. When the piece of food reaches your stomach, another process occurs where digestive juices are secreted. The names of the digestive juices are hydrochloric acid and pepsin. When food enters the stomach through another sphincter, the walls of the stomach actually stretch. This stretching of the stomach stimulates the stomach to release gastrin. Gastrin is responsible for initiating the stomach motor activity and secretion of digestive juices.

The stomach plays a very small part in food absorption and very little food is absorbed in the stomach. The only exception to that is alcohol which is absorbed in the stomach. Those peristaltic movements or contractions mix the food particles into tiny pieces and mix it with the digestive juices and forms what is known as chyme. This chyme is then released into the small intestine.

The small intestine is the work horse of the digestive system. There is where most of the digestion takes place. The contractions and digestive secretions are responsible for breaking down carbohydrates, fats, and proteins that enable the mucosa in your intestine to absorb nutrients into your bloodstream. The bolus of food now known as chyme then enters the large intestine.

The large intestines does not produce any digestive enzymes but it continues the digestive process. This is where through the blood and lymph vessels in the mucosa where most of the water absorption takes place. With the water absorption, it also plays a part in absorbing large amounts of sodium and chloride. The large intestine also is where bacteria hang out. Not all bacteria are bad and they actually play a role in breaking down the food you eat into usable carbohydrates. Bacteria are also responsible for producing flatus and helps to move stool to the rectum. The rectum is located at the end of the large intestine and ends at the anus.

In addition there are accessory organs that are essential to the process of digestion. The accessory organs are responsible for helping with the digestive process. These organs are the liver, gallbladder and your pancreas. These organs supply hormones, enzymes and bile to aid the digestive process.


The liver is responsible for metabolizing fats, carbohydrates and proteins. The liver also stores the essential nutrients iron, Vitamins D, K, and B12. It plays a role in maintaining blood glucose levels and the process of secreting bile.


This organ is located under the right lobe of your liver and is pear shaped. It is responsible for storing and then concentrating the bile produced by your liver. The gallbladder releases bile into the common bile duct and then into the small intestine. Bile is an important part of the digestive process because it breaks down fat and helps with the intestine being able to absorb cholesterol, fatty acids and other types of lipids.


The pancreas lies behind the stomach. It performs functions known as exocrine and endocrine. The exocrine function is responsible for secreting digestive enzymes. The enzyme producing cells release their secretions into your pancreatic duct. The bile duct actually joins the bile duct from the gallbladder right before it enters the small intestine. The endocrine function of the pancreas involves what are known as islets of Langerhans. There are two types of cells involved here known as beta and alpha. The beta cells secrete insulin which are essential in carbohydrate metabolism. The alpha cells secrete glucagon which is a hormone that is responsible for a process known as glycogolysis in your liver. Your blood glucose level are what stimulates the release of insulin and glucagon into your bloodstream.

These are the components of your digestive system and how things function in the human body. When you have symptoms of pain or difficulty with digestion of food a phone call to your physician should be made. Do not delay treatment, waiting can cause things to only get worse. You are the keeper of your body and your health. Good health maintenance is the road to a long and healthy life.

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