So what the hell's the point of puking anyway?

While holding my 22-month-old nephew’s forehead as he wretched with the flu, I got to thinkin’, "What the hell is the real point o’ wretching? When I’m sick with the flu, the virus is already in my bloodstream - too late. When I drink too much alcohol, I don’t puke until the next morning - too late again. And the one time when, as a small child, I drank something poisonous, I had to drink something harmless (ipecac) to induce vomiting anyway. I can’t ever think of a time when involuntary vomiting was helpful. Is this like an autoimmune reflex??

A lot of naturally occurring toxins irritate the stomach lining enough to cause vomiting. It’s a protective reflex. Certain plants, spoiled meat, all sorts of harmful stuff can induce vomiting, which gets rid of the toxin before the body has a chance to absorb it. Of course, we usually don’t eat stuff like that because we’re taught not to. Little kids and animals, though, don’t know better.

Ever had way too much to drink, way too fast? I made the mistake of trying to mix drinks in the semi-dark once, and was puking my brains out within half an hour. Sometimes our bodies have to protect us from ourselves.

It’s also been theorized that self-protection from toxin ingestion is the reason the very smell of rotten meat (rife with bacterial toxins) makes us gag and get nauseous.

Remember, the vast majority of mammals are capable of vomiting (the horse and rat are notable exceptions.) This implies that vomiting arose way on back the evolutionary chain, long before we developed the ability to tell one another, “Hey don’t eat the orange berries or the gray meat, mkay? It tends to make you slightly dead.”

If you drink too much too quickly, you will find yourself puking pretty qiuckly, trust me!

It’s the bodies way of saying “what the hell have you put down your throat? I’m getting rid of it whether you like it or not”.

You know how if you put your fingers down your throat, you start to wretch? Your body thinks you trying to swallow something that’s too big, and it wretches to try to bring it up.

Oh, and Ipecac, from what I understand, is not harmless-it can be very dangerous.

groan

I remember in highschool getting into an argument with a girl over that. I insisted that we evolved the revulsion to the smell of rotting meat so that we would not eat it and die, but she argued that the bacteria evolved the nasty smell so that we would not eat them.
And to think that this girl and I were in AP biology.

At this time, I’d like to note that I absolutely HATE puking. It seems to me that there could be some way that we could get rid of this? Why not the same why we get rid other things? Puking seems so unhealthy, bad for the throat and such. Anyone know if earlier man did it?

It would be worse if you didn’t or couldn’t puke. It’s to get rid of nasty stuff inside you, read the other posts. Humans have been blowing chunks since way before we became human.

Well I knew the “party line” reasons for puking; it just seems my body sucks at determining when to do it.

Sorry to be pedantic, but although it makes you feel wretched, I’m pretty sure it’s spelled “retching”

Horses can get into serious trouble from not being able to puke… they can overeat and then can’t burp or puke to relieve the pressure, and their gut can rupture. And humans are very much like horses in one respect-- if you put lots of yummy food in front of them, they’ll eat and eat and ignore the signals from their body that say ‘Enough food already!’ until it’s too late. In which case the human pukes, but the horse can die.

I’ll find a cite if someone really wants BUT,
puking can be caused by a poison-detection reflex originating in each ear. Some structures behind your eardrum are very sensitive to balance. When you drink, alcohol dulls the ears’ ability to sense balance, so you can’t walk a straight line and get you license suspended.

But what does this have to do with retching?

The brain has a bunch of neurons between the ears that compare balance signals from the two ears. If the timing of the neural signals from the two ears gets out of synchrony, then the brain creates a nausea/puke reflex. But why?

It is thought that altering your body’s chemistry will change the delicate timing of the neurons. So, this timing is a fine-tuned detector of chemical changes caused by poisons. When you get sick from the flu, or drink too much Southern Comfort, the signals from your ears get out of synch, and your body then creates a nausea reflex to reject your stomach contents (i.e. you throw). It’s a safety mechanism to protect you from food poisoning.

When we were evolving 30 million years ago, creatures were more likely to get sick from bad food than from teenage rum parties. So this mechanism makes sense. But the inner-ear protection system is still there trying to save you from your wicked, wicked ways.

It seems pointless to puke with the flu (emptying the stomach doesn’t seem to get rid of the flu), but maybe influenza evolved recently, or maybe flu just spreads a lot faster now because we have malls, 9-5 jobs, big cities, and global transportation.

Y’know, it’s funny, even talking about it can make you kind of…uh, excuse me, gotta go before I…

I don’t know about anyone else, but when I’m full, I stop eating, knowing that I will puke it up if I eat more. It’s a pretty strong signal, and it’s a hard one to ognore. So I really think it would take a lot for someone to completly ogonre that and eat anyway.

FranticMad is right. I’ve suffered for a long time from motion sickness. Every time I got into a car and specially if the trip was longer than 20 minutes, I’d throw up everything I ate. Even when I’d refuse to eat before a trip, I’d still find a way to puke something. So it’s not only about our body getting rid of something it was bad. What was helpful for me was to be sitting on the car seat, hugging my knees tightly. My parents were arguing that that was exactly what made me car sick. So we went to a doctor and he told the that indeed it was an equilibrium problem starting in the inner-ear and that my weird position was in fact helping me to get a certain equilibrium.
My question is: why me? Why not everybody gets car or plane sick?

It takes about 20 minutes for your brain to register how full your stomach is. If you eat quickly then you get that “I ate too much” feeling 10 minutes later. Eating slowly helps you to feel full when your stomach is full. You are probably not a fast fast eater.

FranticMad: I’m a relatively fast eater, yet I quickly know when I’m full, and STOP EATING. I suppose if I kept going I might puke, but I’ve never tried. It’s hard enough to force yourself to eat another bite of even good food.

I’ve heard this, but don’t believe it. I know when I’m full and it’s well before 10 minutes post meal.

As someone who vomited not too long ago, I think that it that the ‘getting rid of toxins’ theory rings true (if only anecdotally). I felt much better after the technicolor yawn.

I’ve heard a slightly different version. Rather than a “a poison-detection reflex” in the inner ear, I’ve heard that alcohol diffuses into the semicircular canals, causing it to change density. This alters the balance signals, which no longer align with the spatial information the eyes convey. Hence the motion sickness, not unlike if you’re being whipped around (by carnival rides perhaps)–because the visual information is direct, whereas there’s a lag due to the inertia of the inner-ear fluid, there’s a disparity in the information sent from the eyes and the inner ear.

Some cites:

http://www.vestibular.org/diet.html talks about alcohol affecting the composition of the inner ear fluid

http://www.worldtravelers.org/motionsickness.htm talks about the cause of motion sickness