Vitals and Bits #2: The Epiglottis
Some body parts, like lungs and the brain, have relatively fancy, white-collar jobs. Other body parts, such as the rectum, take care of the dirty work. Still, other body parts perform their humble trade dutifully without complaint, like a crossing guard who has been ferrying children safely across the street for forty years, rain or shine. The little epiglottis falls squarely into this latter category. And, like so many marvels of nature, it’s easy to take the epiglottis for granted. It just kinda hangs out, doing its thing, and typically its absence is far more noticeable than its presence.
The epiglottis is a flap of cartilage (the type of firm yet flexible connective tissue found in your ear) covered in mucus membrane (or the kind of specialized “wet” skin found in places like the mouth and the vagina.) It is attached to the root of the tongue, way back there inside the throat. The epiglottis is like a lid that sits above the larynx, or voice box. The larynx sits on top of the trachea (aka the windpipe) and is part of the airway. So the epiglottis is essentially a lid perched on top of the airway, but the lid always remains open unless the person is swallowing.
The act of swallowing moves the larynx upwards and causes the epiglottis to fold downwards, so that the epiglottis covers the opening of the larynx. With the airway closed off, food is directed down the esophagus instead, which is the tube that connects the mouth to the stomach. This way, the windpipe remains open during normal business hours so that the person can breath, but is briefly closed off during swallowing to prevent food or fluid from going down the wrong tube and entering the lungs. This is what allows us to eat and drink and make merry without choking to death.
When it’s not called to action during swallowing, the epiglottis also lends a hand to the rest of the body parts in its neighborhood to help out with things like gagging and coughing.
Problems with the epiglottis most frequently arise from dysfunctional swallowing or from infection.
Humans swallow many hundreds of times per day without even thinking about it. But swallowing is actually a pretty high-stakes activity that requires very complex coordination of numerous nerves, muscles, and other bits and pieces. Stroke victims will often lose their ability to swallow properly. When the epiglottis does not completely cover the airway because of faulty swallowing, people end up with food and water and all kinds of nasty stuff in their lungs. Food and junk going down the wrong tube is called aspiration. Significant aspiration will oftentimes lead to pneumonia, so many stroke victims with difficult swallowing will end up with an aspiration pneumonia.
Another problem we see with the epiglottis is infection, which we call epiglottitis. We see this most often in children. Certain bacteria, like Haemophilus influenzae, or Hib, can infect the epiglottis. When this happens, the epiglottis can swell up and occlude the airway. Epiglottitis, which can cause a high fever and a sore throat, is a medical emergency. Difficulty breathing and drooling are red flags for epiglottitis. Fortunately, use of the Hib vaccine in children has reduced the incidence of epiglottitis.
Although the little epiglottis is not the fanciest body part on the block, it makes the two very important acts of breathing and eating possible. And hey, I’m willing to raise my glass and toast anything that lets me enjoy my cupcakes and boxed wine without fear of choking to death.