Pyloric antrum is initial portion of the pyloric part of the stomach, which may temporarily become partially or completely shut off from the remainder of the stomach during digestion by peristaltic contraction of the prepyloric sphincter; it is demarcated, sometimes, from the second part of the pyloric part of the stomach (pyloric canal) by a slight groove.
Synonym: antrum pyloricum, antrum, lesser cul-de-sac