Re: RE: human physiology

> What causes hiccups?

Hiccups result from spasms of the diaphragm the muscle that acts as the 'bellows' for your lungs. The diaphragm is attached to the base of your lungs and along the outer rim of your rib cage, forming a dome above your abdomen. When it contracts, it flattens, pulling the lungs along with it and filling them with air.

          Coronal-section through the chest

      RL|   |LR              RL|   |LR
     RLLL| |LLLR            RLLL| |LLLR          R=Ribs
    RLLLL| |LLLLR          RLLLL| |LLLLR         L=Lung Space
    RLL _____LLLR          RLLLL| |LLLLR         D=Diaphragm
   RLL/DDDDDDD\LLR         RLLLL| |LLLLR
   R/D         D\R         R/DDDDDDDDD\R

      Relaxed               Contracted 
   (=expiration)           (=inspriation)

Usually the nerve that controls the diaphragm suddenly stimulates it, causing it to contract unexpectedly. The diaphragm is an interesting muscle in that it is both a voluntary and involuntary muscle. We can control when and how we breathe. If we couldn't speech would be impossible. However, if you hold your breath long enough you'll black out (don't try this at home!). Once you black out the 'autonomic' nervous system which controls involuntary muscles such as the heart and the muscles of your intestine assumes control, allowing respiration to resume.

> Why do we hiccup, does it serve some physiological function?

I know of no physiological process served by hiccupping.

> How can hiccups be stopped?

A spoonful of sugar, a sudden fright.. a cure I heard from a Russian was to hold your breath while taking 10 small sips of water. For some people these may work. The suddent fright may stop the intermittent stimulation to the diaphragm coming from the brain. Holding your breath while sipping water may work by keeping the diaphragm contracted. The best cure I have tried is based on pressure points used in accupuncture - push very hard against the cartilage ridge that runs horizontally from the back of your ear to just above the beginning of the ear canal. I don't know how it works, or if it's some psychosomatic effect, but every time I've done it, it stops my hiccups.

-P.R.