What keeps food or fluid from going back up the esophagus to the lungs?

Answer 1

If you are vomiting it does. But usually food doesn't go back into the esophagus because it tends to go down hill, going back into the esophagus is going against gravity.

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Also, the lower esophageal sphincter normally prevents stomach contents from flowing backwards. Sphincters are rings of muscle that open and close to control the flow in various places in the body.

Answer 2

The esophagus performs peristalsis, contraction of muscles to push food in a certain direction, in this case, toward the stomach. The stomach is also in a lower position from the esophagus , meaning that for food to get up, it would have to contend with gravity, and that the food is sitting t the bottom of the stomach, away from the exit of the esophagus. Also the esophagus has a valve that prevents food from moving out unless it needs it to.

Answer 3

There is a sphincter muscle that squeezes the esophagus closed unless someone is swallowing. Sometimes a problem occurs in which this sphincter does not close all the way, and stomach acid can come up the esophagus, causing burning and pain.

Answer 4

There is a structure at the entrance to the stomach called the esophageal sphincter, which can contract and seal off that opening, to keep food and digestive juices inside the stomach.

Answer 5

The sphincter .

Answer 6

lower esophageal sphincter

Answer 7

esophagus