why do we yawn,sneeze n have hicupz??

Answer 1

Sneezing is typically caused by an irritation and sometimes bacterial clog up in the throat and ears, lungs, or in the passages of the nose, but even loud noises, and bright lights can be considered an action. Sneezing being a semi-autonomous action, the body goes on the defense and responds to this attack on your nasal passages by forcing the air out.

A previous long-standing hypothesis is that yawning is caused by an excess of carbon dioxide and lack of oxygen in the blood. This can not be proved other hypothesized causes are tiredness, stress, over-work, or boredom., an action indicating psychological decompression after a state of high alert, means of expressing powerful emotions like anger, apathy, remorse . But yawns are also contagious notice that usually when someone else yawns we tend to as well.

hiccuping is an involuntary spasm of the diaphragm it's unknown why but they suggest that one beneficial effect of hiccups is to dislodge large chunks of food, which have become stuck in the esophagus, or which are traveling too slowly.

Answer 2

The human body is an amazing piece of machinery. The simple yawn, a body reaction to the low oxygen content of the body or a definitive signal that the person you're speaking with has exhausted his time limit and your meter is closed; the sneeze is the body's reaction of foreign elements being expelled out of the body or a signal by your date that bathing in a gallon of AXE is not going to get you what the commercials display; and the lowly hiccup is the body's reaction to indigestion or some irritation of the diaphragm or a certain signal that your alcohol tank is nearly full, where the epiglottis is performing a break dance amid the confines of the esophageal crowd. Tough crowd!

Answer 3

Yawn: lack of oxygen in brain
Sneeze: defense mechanism of the immune system
Hiccup: the diaphragm moves upward during inhalation and forces the air back out