WorldwidePies t1_ixanf6x wrote
There are 2 aspects at play here.
Microorganisms and/or their toxins do their actions on stomach cells and cause cellular destruction, which creates pain that is perceived as stomach cramps.
The destruction causes inflammation of the stomach mucosa. The afferent portion of the vagus nerve will be stimulated by either :
… the inflammation, like with Fusarium infection with its vomitoxin.
… or by the toxin itself, like with Bacillus infection with its emetic toxin.
Either way, a nervous signal is sent to multiple structures in the hindbrain, including the reticular formation and the dorsal motor nucleus of the vagus. These respond by sending an efferent influx through the vagus nerve to have the stomach muscles contract, in an effort to induce the emetic reflex (vomiting). This also causes stomach cramps.
Vomiting the microorganisms and their toxins is a protective mechanism that helps prevent the passage of theses substances to the small intestines, where they could be absorbed to the blood stream and cause much more damage.
SansaLaMensa t1_ixbinal wrote
Wow! Thank you for explaining this. I have another question. Should anyone try and take vomit relief/stopping medication? If it works, then could you be setting yourself up for more severe consequences if the body cannot rid itself of whatever is making it sick? Thank you.
ocombe t1_ixc02ol wrote
It depends on what's causing the vomit, but yes it's possible that's it is not helping, the same way that anti coughing medicine is usually not a good idea (unless you're coughing because of an irritation)
No-Quality6765 t1_ixchmfi wrote
During N/V bouts, the toxins are being evacuated as well fluids and electrolytes. On top of dehydration, electrolytes such as Sodium, Potassium will be severely out of balance, which can then lower the threshold for critical dysthymias. College students do the same thing by overloading on energy drinks!
DRD_85 t1_ixeubyn wrote
For vomiting, yes. For diarrhea, ehhh not so much...but the jury is still out on that. It really depends what bacteria or virus has infected your gastro tract. With diarrhea, the main concern is the strain of E. coli that produces a toxin that can cause kidney damage if not treated...although this does not happen to everyone that is infected by that bacteria.
If you go to the ER for vomiting, chances are they will give you ondansetron (or a similar anti-emetic). In most people, this will stop the vomiting within 15 to 30 minutes and allow the person to drink fluids. Obviously, if it didn't stop, they would give you an IV.
The point here is that the toxins causing the sickness are unlikely to cause harm to your body if you block the 5HT-3 receptor they are binding to and activating. Vomiting as it relates to the gastro tract is controlled pretty much exclusively by serotonin and the 5HT-3 receptor.
For example, if you eat something and it irritates your stomach and small intestinal mucosa (not because of bacteria or viruses....think eating like a whole carolina reaper pepper or something similar that is irritating), certain immune cells will become activated by the inflammation and will release serotonin. That serotonin will then bind to and activate the 5HT-3 receptors which will directly stimulate the vomiting center in the brain. Obviously, the reason animals evolved this mechanisms was help expel noxious foods and make us adverse to them in the future.
Now, another example is food poisoning. There are many types, and I won't go into crazy detail. Let's consider the most common...Staph food poisoning. Certain strains of Staph that find their way into food (think somebody handling food with their bare hands) will grow and produce an emetic toxin (if the food is not stored properly). This toxin, if ingested, directly binds to and activates that 5HT-3 receptor...i.e. it directly activates the vomiting center in the brain. These bouts tend to be short in duration with no lasting effects. Therefore, taking a damn anti-emetic (like generic Zofran...ondansetron) is fine. All it does is bind to and inactivate the 5HT-3 receptor in the gut. It literally just blocks either serotonin or toxins from binding and activating the receptor.
So, the next time you are sick to your stomach and it is dragging on, call your doctor and ask for ondansetron. The huge benefit to this medication is that it normally works very well and will allow you to re-hydrate...and we all know that is the most critical part of gatro illnesses.
DRD_85 t1_ixezx62 wrote
Great post and explanation!
However, I would like to discuss the last sentence. Wouldn't you agree that "Vomiting the microorganisms and their toxins is a protective mechanism that helps prevent the passage of theses substances to the small intestines...." is not necessarily a protective mechanism in animals but is, in reality, a mechanism evolved by microorganisms to facilitate their spread in the environment?
I would argue that animals evolved the vomiting reflex to deal with toxic and irritating chemicals found in plants and the environment in general. My evidence would be that the vomiting reflex is controlled by our own endogenous serotonin and 5HT-3 receptors. If we ingest an irritating chemical, the inflammatory response causes an acute release of serotonin in the gastro tract which can lead to activation of the 5HT-3 receptors and vomiting.
When it comes to microorganisms, some have evolved proteins over time that can also bind to and activate the 5HT-3 receptor directly.
However, I will concede that infection by microorganisms themselves can cause localized gastric irritation (by way of activation or our own immune system) which can lead to release of gastric serotonin. But, again, this inflammation is just a localized immune response....same thing that could happen with an irritating chemical from a plant.
In the case of vomiting directly from the toxins produced by microorganisms, I still say that is not a protective mechanism. The human body does not "know" it has been invaded by a toxin, so it therefore is not itself activating the vomiting reflex spontaneously because of the toxin. The toxin is literally binding to the receptor that activates the vomiting center.
I suppose it's a bit of which came first...the chicken or the egg.
WorldwidePies t1_ixk0a4e wrote
I would not agree that the vomiting reflex doesn’t protect the animal. Clearly, the sooner the irritating substances are cleared of the gastrointestinal tract, the better for the animal’s health. The animal doesn’t have to « know » anything to be protected by a reflex, just like taking your hand off the hot stove protects you before the brain event feels the heat.
I would also not agree that the vomiting reflex of animals was evolved by the microorganisms, because that’s not how evolution works. The development of the sensory apparatus needed to sense the irritation, and then to provoke the necessary contractions to induce the vomiting is the result of the animal (not the microorganisms) population’s genetic changes and selection, with the animals that developed that reflex being fitter to face off infections.
I’ll agree that some microorganisms may have evolved to produce increasingly irritating substances so as to provoke vomiting with evermore efficiency because this could benefit them with the dispersion aspect.
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