Parts of the Digestive System and Their Functions

Ever wondered how the human digestive system works? The digestive system is a series of organs that convert food into nutrients that can be used up by the body. The organs also play a critical role in the removal of unused material from the body. The digestive system, also known as the gastrointestinal tract, is made up of the mouth, esophagus, stomach, small intestine, large intestine, rectum and the anus. Read on to find out more about the digestive system parts and functions.

Digestive System Parts and Functions


This is where the process of digestion begins. The smell of food itself triggers the secretion of saliva by the salivary glands in the mouth. Saliva contains the salivary amylase enzyme which helps in the breakdown of starch. In the mouth lies the tongue, which is vital for mixing and tasting food. Teeth help in the grinding of food.

Pharynx (Throat)

The throat or pharynx is a funnel shaped tube that is connected to the mouth. It is charged with passing chewed food into the esophagus from the mouth. It features an epiglottis which is used as a switch to control entry of air and food into the larynx and esophagus respectively.


After you have swallowed your food, it passes through the throat and into the esophagus. Here, food is passed through the hypo-pharynx and the oropharynx. Through a process called peristalsis, food is converted into a small round mass and transported into the stomach. At the end of the esophagus, there is a muscular ring called the cardiac sphincter. It is responsible for closing the end of the esophagus in order to trap food in the stomach.


In the stomach, food is coated with a mixture of digestive enzymes and acid. This helps break down food. The stomach walls are protected from the acid released into the stomach by a thick coat of mucous. After food has been broken down in the stomach, it is then passed on to the small intestine.

Small Intestine

The small intestine is divided into 3 parts: the duodenum, the jejunum and the ileum. The walls of the small intestine have finger-like projections called villi. They facilitate the absorption of nutrients into the bloodstream.

Accessory Organs

In the duodenum (the first part of the small intestines), carbohydrates, protein and fats are broken down with the help of enzymes from the pancreas. Bile juice is released from the gall bladder to further break down fats into a form that the body can use.

Large Intestine (Colon)

After the small intestine, we have the large intestine which is charged with absorbing water and breaking down waste. It contains bacteria that help with the breakdown of waste that is passed on from the small intestine. Once the remaining nutrients are extracted, it becomes feces that are excreted through the anal canal.

Rectum and Anus

The rectum receives stool from the large intestine. When this happens, your body lets you know that you need to pass stool. It is the rectum’s job to hold the stool until it is evacuated. The stool is passed on from the rectum to the anus for ejection. The anus is surrounded by sphincter muscles that allow you to control the anus function.

To Maintain Digestive Health

To ensure your digestive system performs optimally, you need to maintain digestive health. Here are some tips on maintaining optimal digestions:

  1. Eat foods that are rich in fiber such as whole grains, vegetables, legumes and fruits.
  2. Make sure your diet includes both soluble and insoluble fiber. Insoluble fiber cannot be digested by the body and adds bulk to your stool.
  3. Limit the intake of fats as they slow down the digestive process. Go for lean meats such as skinless poultry and pork loin.
  4. Include probiotics in your diet. These are healthy bacteria that are needed for optimal performance of the digestive system. Examples include kefir and low-fat yoghurt.
  5. Try to schedule your meals such that you are eating at the same time every day. This helps keep your digestive system in tiptop shape.
  6. Drink lots of water. It helps dissolve fats and soluble fiber.
  7. Avoid smoking and excessive alcohol and caffeine. They can cause stomach ulcers or interfere with digestive process.
  8. Exercises keep the food moving through the digestive system.
  9. Keep stress levels under check as they can disrupt your digestion. 

To maintain the optimal digestive system parts and functions, make sure to follow the above advice.

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