On Thu, 27 Aug 2009 18:03:29 -0400, Goomba wrote:

> blake murphy wrote:
>
>>
>> cecil's article says it has something to do with stimulation of the vagus
>> or phrenic nerves.
>>
>> your pal,
>> blake
>
> phrenic. The phrenic nerve is the major nerve that innervates your
> diaphragm and allows you to move the diaphragm allowing you to breath.
> When the diaphragm is irritated (for many reasons) that can cause hiccups.

cecil says it can be either:

Lots of other things can cause hiccups too, some of them pretty scary.
Skimming through a long list, I see skull fracture, epilepsy, diabetes
mellitus, myocardial infarction, tuberculosis, meningitis, bowel
obstruction, and ulcerative colitis.

But it's not always, or even usually, so bad. A 27-year-old man complained
that he'd been hiccuping for four days. The doctor looked into the guy's
ear and saw a hair tickling the eardrum. The hair having been washed out,
the hiccups stopped.

[...]

Or maybe they're just, you know, hiccups--an accidental reflex triggered by
a stimulus to (usually) the vagus or phrenic nerves. This travels up the
line to a nerve control center that for some reason sends out a "commence
hiccup" impulse via the phrenic nerve.

The vagus and phrenic nerves go all over, which explains why so many things
cause hiccups. For example, a 16-year-old girl began hiccuping after
receiving a blow to the jaw. A brain scan found that a blood vessel was
pressing against the vagus nerve in her neck. Surgeons inserted a Teflon
spacer between the nerve and the blood vessel, and the hiccuping stopped.
When the spacer later fell out the hiccuping resumed.

<http://www.straightdope.com/columns/read/1113/what-are-hiccups-and-why-do-we-get-them>

your pal,
blake