mechanisms of the oesophgeal-gastric valve

Last reviewed 06/2021

The following factors are thought to be important in maintaining a competent gastro-oesophageal valve:

  • the angulation of the insertion of the oesophagus into the stomach:
    • pressure within the stomach is transmitted to the fundus
    • the fundus may then press on the terminal oesophagus preventing reflux

  • there is increased tone in the circular muscle of the oesophagus just before it enters the stomach:
    • this may function as a sphincter

  • the right crus of the diaphragm contracts during severe stress, e.g. sneezing, and closes the oesophagus

  • the length of intra-abdominal oesophagus:
    • the higher pressure in the abdomen as compared to the thorax may keep the oesophagus closed

  • the thick folds of mucosa at the cardia of the stomach may act as a "cork in a bottle"

Hiatus herniation results in loss of the:

  • gastro-oesophageal angulation
  • intra-abdominal oesophagus