Cardiac Sphincter - upper part of the stomach attached to the esophagus where food travels down from the esophagus to the stomach.
Cardiac Sphincter Role
The cardiac sphincter prevents food from passing back to the esophagus. It is the body's main way to prevent heart burn.
As the food travels from the esophagus to the stomach, the stomach secretes acidic digestive juices which can be harmful to the esophagus because they are so acidic. The cardiac sphincter serves as the main barrier. If the food ever travels up from the stomach back to the esophagus, the person may experience heart burn.
Heartburn is simply a burning sensation in your chest due to acid indigestion. The burning sensation is just about where the esophagus is located, just behind the breastbone. In case of slightly more severe heartburn, the pain may radiate and expand in other areas around the esophagus in every direction. Other commonly affected areas other than the breastbone area are the neck, throat, or the jaw.
Feeling heartburn every once in a while in pretty normal as it happens to most people. If you experience this symptom more frequently, you may have, or are at risk of having Gastroesophageal Reflux Disease (GERD). But that is only one of the possibilities. You should never jump to such conclusions. Instead, if you feel something might be wrong, you should seek a correct diagnosis from a highly qualified healthcare professional such as a doctor specializing in gastrointestinal (GI) problems.
One of the symptoms of the gastric juice and some of the gasses that are supposed to be in your stomach going back up into the esophagus is extra belching that smells unusually bad, or what may seem as excessive gas.