What happens to your body when you hiccup

Let's look at what happens when we hiccup.It begins with an involuntary spasm or sudden contraction of the diaphragm,the large dome-shaped muscle below our lungsthat we use to inhale air.This is followed almost immediately by the sudden closure of the vocal chords and the opening between them,which is called the glottis.The movement of the diaphragm initiates a sudden intake of air,but the closure of the vocal chords stops it from entering the wind pipe and reaching the lungs.It also creates the characteristic sound:hic.To date, there is no known function for hiccups.They don't seem to provide any medical or physiological advantage.Why begin to inhale air only to suddenly stop it from actually entering the lungs?Anatomical structures,or physiological mechanisms, with no apparent purpose present challenges to evolutionary biologists.Do such structures serve some hidden function that hasn't yet been discovered?Or are they relics of our evolutionary past,having once served some important purpose only to persist into the present as vestigial remnants?One idea is that hiccups beganmany millions of years before the appearance of humans.