Gag reflex, also called pharyngeal reflex, is a reflex contraction of the throat in humans that prevents anything to pass through the throat, except during normal swallowing. It is also named as pharyngeal reflex.
Touching the soft palate results in a very strong gag reflex in most healthy people. The gag reflex can also be caused by touching the roof of the mouth, or the back part of the tongue. The gag reflex can be used to make someone vomit as well.