The digestive system is composed of the gastrointestinal (GI) tract (or gut), which comprises the oral cavity (mouth), esophagus, stomach, small intestine, and large intestine, as well as ancillary organs like as the salivary glands, pancreas, liver, and gallbladder. The digestive system’s primary job is to take nutrients from ingested food and to remove indigestible leftovers. Additionally, the digestive system acts as a barrier between its lumen’s contents and human tissues, providing immunological protection against infectious disease. The enteric nervous system and both local and systemic hormones regulate the digestive system’s actions.