6.3: Esophagus

Swallowing closes off routes to the nasal cavity and windpipe and sends food down the esophagus. This is why you can’t keep drinking without pausing for breath—as a baby can. Babies can breathe and swallow at the same time, as when they nurse or suck a bottle. Their windpipe doesn’t have to be shut off when they swallow because their short lower face puts the top of the windpipe at the level of the nasal cavity. (This also means that it’s harder for babies to breathe through their mouth.)

The esophagus is straight and short—about 9 inches long and 1 inch wide. Sword-swallowers tilt back their heads to get the sword to go straight down the esophagus; their talent is their ability to suppress the normal gag reflex.* Other than serving as a passageway from mouth to stomach, the esophagus isn’t essential to digestion or life.

Each year in the U.S., thousands of children under age 6 damage their esophagus by swallowing caustic chemicals, mostly household products like drain openers. Sometimes the damage is irreparable, and an artificial esophagus must be surgically constructed.

In earlier times, there wasn’t much a surgeon could do. In 1895, there was the case of a nineyear-old who took a huge gulp of scalding-hot soup, permanently damaged his esophagus, and had to have a permanent opening made to his stomach. He went on to live an outwardly normal life, but ate by chewing his food and spitting each mouthful into a funnel that led to the special opening in his belly.

Before food goes on to the stomach, it passes through a sphincter (a ring-like band of muscle fibers that act to constrict a passageway) located at the junction between the esophagus and stomach. After food goes into the stomach, the sphincter contracts to keep the food from backing up into the esophagus or the mouth.

Sometimes, especially when the stomach is full, stomach acid may splash up past the sphincter into the esophagus and cause pain. It feels like a burning sensation in the chest and is commonly called heartburn. It’s really esophagus-burn, and is especially common after dinner among people who don’t eat much during the day, then eat a large, high-fat dinner.

Heartburn often can be avoided by eating smaller, lower-fat meals, and not lying down afterwards. If eating large, high‑fat meals, it helps to wear clothes that are loose at the waist. Also, drugs that hamper acid production (e.g., Tagamet) can be taken before eating, or antacids (e.g., Tums) after eating. Chronic heartburn should be checked by a physician because it can sometimes lead to cancer of the esophagus.

^{*Alcohol can suppress the gag reflex, making it easier to choke on food when drinking alcohol before or during eating (food gets further down before gagging, and you can’t pull it out like a sword).}