The gastric antrum is the end of the stomach that closes during the digestion of food and opens again to allow the passage of the digested food when the process completes. This part of the stomach is usually called the pyloric antrum.
The general definition of an antrum is a cavity or chamber, and the term is used almost exclusively for referring to a part of the anatomy of an animal or person. The pyloric antrum is just one found in the body of vertebrates, with four more commonly found among these types of animals. Any cavity or chamber found in a living creature can be called an antrum, with only common examples between many species receiving a specific name.
The word pylorus comes from the Greek word for gate guard, due to its function of trapping food within the body. This gate stops food from passing through it before it can be properly digested. This gate is shut by a valve of smooth muscle.
Some medical conditions can constrict this part of the stomach, causing nutritional problems. These problems are usually detected early in life due to vomiting and consistent hunger and can be fixed through surgical procedures to widen the pylorus.