The esophagus is the connecting means of access between the throat and the stomach it is a muscular tube that delivers food from the mouth by using the rhythmic tightening of smooth muscles to push contents to the stomach.
Where the esophagus joins the stomach is called the cardia. At this juncture there is a strong band of muscle that acts like a one way valve mechanism called the lower esophageal sphincter. It works by contracting and closing off the passage to the stomach, preventing the stomach acid from returning into the esophagus. When we eat and swallow the muscles of the LES will open for a short time allowing food to pass to the stomach. It then closes, stopping stomach acid re-entering the esophagus. (Acid reflux).
One of the problems that can happen to the LES is when the ring of muscle looses tone and contracts weakly allowing stomach contents to reflux back into the esophagus.
Another acid reflux cause is called transient LES relaxations. This action is normal and spontaneous and usually occurs after a meal when the stomach is distended. Many of these transient LES relaxations occur to let air out of the stomach and result in “belching or burping”.
In a person without GERD normal Les relaxations happen and sometimes food can reflux back into the esophagus, but strong esophageal muscle contractions should normally force these stomach contents back into the stomach. Also saliva is being swallowed at the same time. The saliva contains bicarbonate a natural acid neutralizer which works to counteract the acid so there is no damage in the esophagus.
Many people who suffer from GERD have more frequent transient LES relaxations as compared to those who have infrequent or no heartburn symptoms. This is because the relaxations can last longer, sometimes a few minuets allowing far more stomach acid to be released into the esophagus causing damage.
Usually Les relaxations do not take place when you are lying down but with individuals that suffer from GERD transient LES relaxations can be brought on at night while lying down and as a consequence from time to time relentless damage to the lining of the esophagus can occur.
