The primary function of the pyloric valve is to impede undigested or large food particles from entering the intestine. It is a cone-shaped valve that connects the end of the stomach to the start of the small intestine.
The pyloric valve is comprised of the pyloric antrum, which connects to the stomach, and the pyloric canal, which leads to the upper region of the small intestine. When the valve contracts, it holds food in the stomach, where digestive juices engage to break down the particles. Once the food is properly broken down, the valve opens and allows the food to enter the upper areas of the small intestine. The valve's mucous-membrane lining secretes essential gastric juices, which prevent intestinal contents from returning to the stomach during intestinal contractions.
The valve's muscular tissue allows it to open or close, which is vital for permitting or retaining food particles during the digestion process. The muscle is commonly relaxed and open to transfer small food particles into the upper region of the small intestine. When the small intestine takes in too much food it puts pressure on the pylorus, which causes the valve to contract and close. The closing of the valve prevents acid reflux by impeding the particles from re-entering the stomach.