Stomach – is a muscular organ located on the left side of the upper abdomen. The stomach receives food from the esophagus. As food reaches the end of the esophagus, it enters the stomach through a muscular valve called the lower esophageal sphincter.

The stomach secretes acid and enzymes that digest food. Ridges of muscle tissue called rugae line the stomach. The stomach muscles contract periodically, churning food to enhance digestion. The pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.

Pancreas – The pancreas is an organ located in the abdomen. It plays an essential role in converting the food we eat into fuel for the body’s cells. The pancreas has two main functions: an exocrine function that helps in digestion and an endocrine function that regulates blood sugar.

The pancreas is located behind the stomach in the upper left abdomen. It is surrounded by other organs including the small intestine, liver, and spleen. It is spongy, about six to ten inches long, and is shaped like a flat pear or a fish extended horizontally across the abdomen.

Small Intestine – The small intestine is part of your digestive system. It makes up part of the long pathway that food takes through your body, called the gastrointestinal (GI) tract. When food leaves your stomach, it enters the small intestine, also called the small bowel. The small bowel connects to the large bowel, also called the large intestine or colon. The intestines are responsible for breaking food down, absorbing its nutrients and solidifying the waste. The small intestine is the longest part of the GI tract, and it is where most of your digestion takes place.

Large Intestine – The large intestine is larger in diameter than the small intestine. It begins at the ileocecal junction, where the ileum enters the large intestine, and ends at the anus. The large intestine consists of the colon, rectum, and anal canal.

Unlike the small intestine, the large intestine produces no digestive enzymes. Chemical digestion is completed in the small intestine before the chyme reaches the large intestine. Functions of the large intestine include the absorption of water and electrolytes and the elimination of feces.

Duedenum – The duodenum, the first and shortest section of the small intestine, is a key organ in the digestive system. The small intestine’s most important function is to digest nutrients and pass them into the blood vessels—located in the intestinal wall—for absorption of the nutrients into the bloodstream.

Together, the duodenum and other organs of the alimentary canal (the pathway by which food enters the body and solid wastes are expelled) form the digestive system of the body.