The stomach is a muscular, balloon-like organ in your abdomen. It temporarily stores boluses of food coming from the esophageal tract and continues the digestive process through mechanical and chemical digestion. Food in the stomach turns into a thick, fluid-like substance called chyme and eventually passes into the small intestine.
The stomach is primarily composed of four regions – the cardia, fundus, body and pylorus. The end of the esophagus is attached to the stomach at the cardia. Just above the cardia is a dome-shaped area called the fundus, which contain gastric glands that secrete a mix of gastric juices.
The largest area of the stomach is called its body. Its surface folds into itself as ridges called rugae that maximize the amount of digestion that the stomach can carry out. Both the gastric juices that the stomach produces, and its own churning motion, contribute to digestion.
After six to eight hours, chyme will slowly exit the stomach through the pylorus. This region connects the stomach to the duodenum of the small intestine.
While an empty stomach is fairly small, being the size of your fist, it can stretch to 75 times that size to accommodate as much as four liters of food and drink.
We’ve constructed this stomach diagram labeled with the regions of the stomach to clearly visualize how food continues its digestive process before entering the small intestine.