Human Digestive System

Human Digestive System

The digestive system is important as it helps to break the complex food into simpler substances like glucose, amino acids. The essential nutrients are absorbed in the body for providing energy, growth and repair of cells.

All living beings need food for growth and to get energy. The food we eat is broken down by the digestive system that provides energy to each and every cell of the body. The Human digestive system performs the complex action of digestion with the help of various organs and the fundamental digestive juices. The energy released from the breakdown of food is distributed in the entire body. This food also helps in the growth of the body and repairment of the cells.  The main function of the digestive system is to convert complex food items into “amino acids, glucose, and fatty acids”. The broken food is absorbed in the bloodstream and the essential nutrients reach each cell in the body. The digestive tract begins at the mouth and ends at the anus. 

Importance of the Digestive System

Digestion is important as the body needs nutrients from the food we eat and the water we drink in order to stay healthy. Carbohydrates, fats, proteins, minerals, and vitamins are the important nutrients that have to be absorbed by the body. The digestive system performs an important role in breaking the food into smaller units for growth, energy, and cellular repairs. The Human digestive system consists of the digestive tract that is almost 10 meters long and the digestive organs are attached all along the way. The food cannot be absorbed by the bloodstream until it is broken into small units. 

Movement of food through the gastrointestinal tract

All the organs that consist of the digestive system help to move the food through the GI tract. The food is broken down by the digestive juices released by the organs. The Human digestive system comprises Mouth, Esophagus, Stomach, Small Intestine, Liver, Pancreas, and Large Intestine. Once the food is broken down into smaller units the body can absorb and move the nutrients to the target cell. The food enters the body initially through chewing. 

The peristaltic movement of the esophagus helps the food reach the stomach. The stomach mixes the food with the digestive juices and breaks down the food further. Then the food passes to the small intestine where it is mixed with juice from the liver, pancreas, and gallbladder. Further, the peristaltic movement in the large intestine helps to absorb the important nutrients in the bloodstream. The products which are unnecessary or the food products reach the rectum and are excreted out of the body through the anus. 

Breakdown of food in the digestive tract

The food is broken down in the digestive body with the help of motions such as chewing, mixing, and squeezing. The saliva in the mouth is also a digestive juice that softens or moistens the food. The saliva also contains an enzyme that is capable of breaking down starch in the food. 

The glands in the stomach secrete acids which help to break down the complex carbohydrates. Also, Pancreas secretes digestive juices that break down fats, proteins, and carbohydrates. The bile juice is secreted by the liver which helps in the digestion of fats and vitamins. Pancreatic juices complete the breakdown of important nutrients such as carbohydrates, protein, and fat. The Human Digestive System, therefore, maintains all the important functionalities that convert the complex food substances into simple absorbable nutrients

Working of the digestive organs

The important digestive organs of the body are the mouth, esophagus, stomach, small intestine, pancreas, liver, large intestine. Let us see the function and working of each organ in brief-

Mouth and esophagus

The digestion begins in the mouth and the grinding action is done by the teeth. The saliva moistens the food and makes it easier for swallowing. Saliva has a special enzyme that triggers the breakdown of carbohydrates into simple sugars, The muscular contraction, and relaxation of the esophagus help to swallow the food. 


It is a J-shaped bag that mixes the food with gastric juices. The food is passed through the sphincter into the muscular bag. The stomach helps in churning the food and helps in breaking the food chemically and mechanically. The stomach passes the food to the small intestine

The small and large intestine

Small intestines mix the food with more digestive enzymes. The food is then squeezed to the lower parts where the food is absorbed by the special organs called villi and directly passes to the bloodstream. The waste products which have not been absorbed move to the large intestine through a bowel movement. 

Liver and Pancreas

The liver breaks down fat by secretion of bile and the pancreas helps in the secretion of digestive juices 

Significance of digestive juices

Digestive juices mainly create digestive food conditions and it can be seen that the nutritious factors can be absorbed by the body after the food is mixed with the digestive juices. The digestive juices are mainly saliva, pancreatic juices, gastric juices, succus entericus or intestinal juice and as well as bile. These juices are secreted in different parts of the digestive process. 


The digestive system, therefore, performs crucial actions which are responsible for the growth of the body and the production of energy. The complex action of the organs and juices helps to maintain the smooth functioning of the digestive system. The digestive system breaks down proteins into amino acids, fats into glycerol and fatty acids, and carbohydrates into simple sugars like glucose.