Digestive System is one of the key body systems, responsible for processing nutrients in food and ensuring the body receives enough energy to sustain itself and grow. As shown in the below diagram, human digestive system consists of the following parts: mouth, throat, stomach, intestines, bladder, rectum, anus, liver, colon, and other organs. Now lets explain what each organ is responsible for in the system.
Mouth is responsible for food intake and initial digestion with chewing and saliva beginning the food breakdown. The food then travels through the throat (pharynx) to the esophagus, which is a muscular tube-like organ connected to the stomach. Esophagus has a special valve, which prevents food from going backwards.
Most of the digestion happens at the stomach. Stomach acid breaks down the food into a paste-like substance. This substance then moves into the small intestine, where part of the food is still being broken down while most of the nutrients get absorbed into the blood. Pancreas, liver and gallbladder all support the functioning of the small intestine. The remains of the processed food move into the large intestine (colon). This is where stool is formed and processed. From a liquid like state, the stool hardens as water is further absorbed. The waste is then moved into the rectum. The digestive system diagram below shows the various organs in the described system.
Also see other human organ systems