What is the Punching Bag in the Back of Our Throat and Is It What Makes Us Gag?

Everyone has taken a look in the back of someone else’s throat (or even your own with a mirror) and seen a “punching bag” or “dangly thing”. This “dangly thing” is actually called a uvula . The uvula is made of mucus membranes, connective tissue, and muscle. The roof of the mouth is divided into two sections, the hard palate and soft palate (refer to the diagram). The uvula hangs from the soft palate, and is located above the back of the tongue.

A diagram of the inside of the mouth

A diagram of the inside of the mouth

So what exactly does the uvula do? For a while no one knew the answer. There were several different hypotheses that went around, with the most extreme being that it was a hazardous organ causing sudden infant death syndrome. This was disproved (and we now know how to disprove a hypothesis thanks to Andrew). A study was conducted in 1992 to find the purpose of the uvula. One thought that one purpose of the uvula is to assist with drinking while bending over. This previous assumption was that the uvula was a “leftover” organ from evolution, developed for when mammals needed to bend over to drink something. This was proved not true, because after the palate of eight different mammals were studied, an underdeveloped uvula was only found in two baboons. Two things that truly separate us humans from animals are speech and having a uvula. The conclusion from the study is that the uvula could be an organ to help aid speech. This is now confirmed. Another purpose of the uvula has to do with swallowing, but not upside down like originally thought. While swallowing, food is intended to go down your throat (obviously). The uvula is there to block the passage into the nasal cavity and makes sure your food stays out of your nose (yuck, thank you uvula).

Many people attribute the uvula to their gag reflex. This is also true. A gag reflex is the contraction of the back of the throat, triggered by an object touching the back of your tongue, tonsils, back of your throat, and your uvula. The gag reflex purpose it to prevent choking. The gag reflex is first and mainly used during infancy, and is supposed to help moderate the transition from liquid to solid foods. When an object that is deemed too “large” or “chunky” for a baby’s stomach to digest (causing the object to come in contact with the uvula), the gag reflex expels substances the brain triggers as harmful. Once babies are about 6 months, their gag reflex disappears, and they are able to start eating solid foods. The gag reflex is only triggered in children and adults when an unusually large object is placed in the mouth. To confirm that the uvula is related to gagging and not just the other areas in the back of the mouth, another study was done. A controlled, double blind experimental study on volunteers (we all know what this means from class) evaluated the gag reflex by using nitrous oxide to suppress experimentally induced gagging. The study found that the subjects who did nitrous oxide inhalations tolerated a much “more intrusive oropharyngeal stimulation than under control conditions”.

A diagram highlighting the gag reflex "trigger points"

A diagram highlighting the gag reflex “trigger points”

To conclude, the uvula does in fact have a purpose. The uvula helps direct food down the throat, assists with speech, and helps to trigger the gag reflex. Hopefully from reading this you will always remember that the punching bag in the back of your throat does have a name and a purpose.

P.S: While the following was not part of my main research topic, I did find it very interesting and wanted to include it: Although it is not an intended function of the uvula, it assists with snoring. It vibrates and is part of the reason you hear what you hear when you listen to someone snore. Side note: In very rare cases, there is actually a surgery (uvulopalatopharyngoplasty) to remove your uvula and surrounding tissues. This surgery is only done in VERY extreme cases of snoring problems.