The uvula is the dangling flap of flesh located at the back of the throat. The purpose of the uvula is somewhat uncertain, even today, but it is part of the soft palate at the top of our mouth and throat. The palate and uvula move upwards when we swallow to prevent solids or liquids from moving into our nasal cavities. When we swallow, the uvula moves upwards against a muscular ridge, keeping our mouth and nasal passages separate. Laughing while drinking something disturbs the seal which causes the beverage to come shooting our of our nose.
The uvula and soft palate are also responsible for snoring in some people. The tissues vibrate as the person breathes while asleep, which is what causes the sound. Sleep apnoea is a condition in which tissues in the throat, including the uvula, obstruct air passages during sleep, causing brief interruptions in breathing and constantly disrupting a person's sleep patterns.