The
pharyngeal reflex or
gag reflex (also known as a laryngeal spasm) is a
reflex contraction of the back of the throat, evoked by touching the roof of the
mouth, the back of the
tongue, the area around the
tonsils, the
uvula, and the back of the
throat. It, along with other aero digestive reflexes such as reflexive pharyngeal swallowing, prevents something from entering the throat except as part of normal
swallowing and helps prevent
choking.