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Cardiac Sphincter: Location, Structure, and Function

Cardiac Sphincter: Location, Structure, and Function

The cardiac sphincter is a circular muscle located at the distal end of the esophagus. It relaxes to allow the passage of ingested food into the stomach, and constricts so that contents of stomach do not move back to the esophagus.
Nicks J
Did You Know?
People suffering from poor functioning of the cardiac sphincter should avoid fried foods as they can aggravate the condition and frequently cause acid reflux symptoms.
While having a meal, the food that is ingested passes through a tubular structure known as the esophagus (throat), and finally, it enters the stomach where it is broken down for digestion. Have you ever wondered why the food ingested to the stomach does not flow backwards to re-enter the esophagus? Well, this is due to the presence of the cardiac sphincter that lies at the end of the esophagus. This vital organ of the digestive system is discussed in detail below.
Cardiac Sphincter Function
The cardiac sphincter that lies at the lower end of the esophagus acts like a valve that ensures unidirectional flow of ingested food. To be more precise, it is located between the distal end of the esophagus and the stomach. Also known as the lower esophageal sphincter, it opens and allows the food to enter the stomach.

Once the food passes through the esophagus, the sphincter closes so that the food does not flow back out of the stomach. Stomach acids that are secreted to promote digestion also cannot flow back and enter esophagus as the sphincter remains closed. Simply put, its job is to prevent the contents of the stomach from flowing upwards or in the opposite direction.
The sphincter is a ring of muscular tissue that contracts to close the passageway. It is a thick circular muscle wall that regulates the movement of food from the esophagus. The contraction of muscular ring seals off the esophagus. When we swallow or ingest food, the sphincter relaxes and the passage opens, thereby allowing food to move into the stomach. The sphincter remains closed most of the time, and opens only when consuming food. This relaxation and contraction of the cardiac sphincter at the right time is vital to prevent any sort of digestion problems.
Cardiac Sphincter Problems
When the cardiac sphincter is not functioning properly, it gives rise to a common digestion problem, referred to as GERD (Gastroesophageal Reflux Disease). People affected with GERD suffer from regurgitation, meaning the contents of the stomach, which includes food, liquids, and stomach acids, can easily flow black and reach the esophagus. A weakened cardiac sphincter is not capable enough to stop stomach contents from accessing the esophagus. Some of the common symptoms associated with GERD include nausea and heartburn (chest discomfort). So what was eaten previously may suddenly return to the esophagus, giving the patient a serious heartburn.

As far as treatment for weakened cardiac sphincter is concerned, medication may be prescribed so as to increase the tone (tightness) of the sphincter. Diet as well as medicines that help inhibit secretion of stomach acid may also be recommended to alleviate GERD symptoms.

However, when the sphincter is damaged significantly, a surgical construction of sphincter may be recommended. Surgical implants consisting of titanium beads having a magnetic core, are also available, which give extra strength to the sphincter so that it functions normally. This ring-shaped implant is found to be effective at curbing the symptoms of GERD.
Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.