Where the action is.

I recently learned about an interesting section of the brain, one that gets a lot of use for a lot of people, maybe especially us Mets fans. I did not know that there was a part of the brain specifically devoted to dealing with this common issue. I am, of course, referring to the vomiting center. 

The Encyclopedia Britannica says that "Vomiting is believed to be controlled by two distinct brain centres—the vomiting centre and the chemoreceptor trigger zone—both located in the medulla oblongata."

It's a happening place.

That medulla oblongata is like the O'Hare Airport of embarrassing bodily functions, including sneezing and coughing. Since it handles digestion as well, I will assume it has a farting center or the like. It definitely has its own vomiting center, which is the gate of this airport we're looking at today. 

I guess I always thought that vomiting just kind of happened. The stomach and the senses could take care of business, and the brain's only concern was to butt out and get the body to a toilet, stat. But no, the brain's got to be in the thick of things no matter what.  

So how does this thing work to make for emesis? (Emesis is a pleasant way to say an act of vomiting.) The medulla oblongata contains that cool-sounding chemoreceptor trigger zone, and when the CTZ gets word from the blood that the stomach ought to remove its contents quickly, it telegraphs the nearby vomiting center. "Hey, VC, we got a problem," it says, and before the vomiting center can get any details it's already sending the EVAC notice to the glands and muscles involved in hurling. The vomiting center does not screw around. It takes its job seriously. 

Okay, that explains throwing up from food poisoning, drunkenness, chemotherapy, and opiates, among other things. But what about when there's no actual poison in the system? you wonder. What if you're seasick? 

That's actually a good question, and I'm glad I thought of it. The Merck Manual tells us that "The exact pathophysiology is undefined, but motion sickness occurs only when the 8th cranial nerve and cerebellar vestibular tracts are intact; those lacking a functional vestibulo-cochlear system are immune to motion sickness. Movement via any form of transportation, including ship, motor vehicle, train, plane, spacecraft, and playground or amusement park rides can cause excessive vestibular stimulation." 

So excessive vestibular stimulation is somehow involved, although how it causes the vomiting center to light up like the Christmas tree in Rockefeller Center is a matter of debate. Its efficiency is, however, undeniable, especially at the fairgrounds when your child comes off the Spindizzy Heavemaster ride and lets the stew of corndog and chocolate ice cream fly on your new Jumpmans. 

The human brain is an absolutely amazing biological construction, but sometimes it seems like it's being controlled by a moron. Like a high-tech cutting-edge experimental jet being controlled by a chimpanzee using an Etch-a-Sketch. And that's not even considering the stupid things we do on purpose. On that topic I could blog every day for a year.