Uvula image via Shutterstock

The uvula is one of the weirdest looking features of the human body. Yet despite its infamy, scientists have spent centuries puzzling over its function.

The hangy ball's full name is the “palatine uvula,” referring to its location on your soft palate. Not to be confused with the uvula vermis, a lobe of the cerebellum, or the uvula vesicae, in the urinary bladder. 

Through history, scientists have had many theories about the uvula. Among them:

That it once helped guide the flow of food and water, and, in humans, was a mere remnant from previous mammals who had to lean down to eat and drink.
That it induces the gag reflex. And therefore isn’t the best place to get a piercing.
That it contributed to “chronic cough.” A problem that 19th-century doctors treated with a “simple” “clipping” procedure.
That it contributes to cardiovascular problems like sudden infant death syndrome (SIDS) and sleep apnea.

Even today, some doctors treat sleep apnea by having the uvula removed. Unpleasant as that sounds, much of the recent uvular research has come about by studying uvulopalatopharyngoplasty patients (uvula-less people). Several such studies have concluded that the uvula is really good at excreting saliva. A lot of saliva, in a really short amount of time. Another study compared the soft palates of eight different mammals, and found that a small, underdeveloped uvula was found in only two baboons.

Don’t Leave Us Hanging

So what does the dangly throat thing do? Because the uvula is basically unique to humans, scientists basically agree that it primarily serves as an accessory to speech. You know what it’s like to have your throat go dry before talking to a large group? The uvula is there to provide the proper lubrication for complicated human speech. In time, we’ll likely learn that the uvula does some other cool things to boot, but to quote one study on the subject, it “may be another marker of human evolution that differentiates man from other mammals.” For now, that’s pretty cool.

This post originally appeared in 2012.