The function of the pyloric sphincter is to...?

Pyloric sphincter is located at the base of the stomach and is the contracting ring of muscle which guards the entrance of the to small intestine. It keeps the stomach shut at the far end so that it has a chance to digest proteins, then it opens and allows the contents of the stomach, now called chyme, to pass through the pyloric sphincter and enter the small intestine; the first section is called the duodenum and it does the majority of digestion and some absorption.