The human body is a complex system that consists of a number of organ systems working in sync together for the sustenance of life. Even if one of the organ systems is absent or is malfunctioning, then it can affect the entire body system. The human digestive system, also called the gastrointestinal tract or GI tract, is one such system whose main function is digestion. Food and drink, when consumed, need to be broken down into small parts so that the body is able to use them for nourishment and energy. Digestion begins in the mouth and ends in the small intestine. The food in the mouth is mixed and digestive juices, and is broken down into smaller molecules. It is then pushed into the stomach, where further digestion takes place. The digested food is assimilated in the blood and transported to the entire body. If you observe the diagram of the digestive system, you will notice that it is made up of different organs that function together. And the help of the explanation provided, you can understand the working mechanism of this organ system. The mouth or the oral cavity is the starting point of the digestive system. The buckle cavity has a set of 32 teeth, a tongue, and salivary glands. All these parts help in the chewing and breakdown of food. There are three types of salivary glands, categorized according to their placement in the mouth - parotid, submandibular and sublingual. The salivary glands release that partially digests the food in the mouth before it is passed to the stomach through the esophagus. There is also another part in the oral cavity in the throat, known as the pharynx. The pharynx is the common pipe for the esophagus and the trachea (also known as wind pipe). The main function of the pharynx is the passage of food and air to the respective organs.