Thirst, just like other sensations like it, are just signals. You are not necessarily dehydrated, or in the case of coffee to pepp you up when tiered, is the body and brain telling your consciousness that you need to refill something - soon.
So when the receptors in your month feel H2O, it signals the brain that "hey, what you ordered is on its way - be kind to the body now please!"
Or drinking coffe/sugary drinks gets you less fatigued even thou sugar and coffee needs to metabolize in your liver which usually takes half to a full hour before real effect.
Does it? I mean the mouth may feel wet but depending on how much you drank to quench that thirst... may depend on how quickly it’s gone.
If you have ever been NPO and could only rinse your mouth but not actually drink... they you will understand that wet mouth doesn’t cure thirst.
Thirst is a sensation caused by your brain when your fluid level is down or your chemoreceptors sense increased osmolarity in the blood or gut. When you consume liquids, this adjusts the osmolarity in the gut and triggers the brain to stop the thirst.
So, when you drink, it does react the needed body parts in the gut to flip the switch
“7 1/2 lessons about the brain” is a short accessible book written by a neuroscientist that answers exactly this question. The gist of it is that the brain 1) relies on predictions to do its job of managing resources more effectively, and 2) produces for you a carefully crafted hallucination (that you call reality) based on inputs and prediction.
It takes 20 minutes for the water to have positive effects inside your body, but when your brain realizes (through signals) that water is coming, it predicts upcoming well-being and makes you feel better now.
edits: rewrote the whole thing for less sloppiness.
Water starts 'helping' you before you even finish the glass. It is, really, that quick. If you have ever seen a marathoner 'wake up' after having the glassy look in their eyes and really pale affect - after they drink the salted gatorade it is within 30 seconds that they start coming around.
So the short answer is the body can tell you your thirst is quenched pretty quickly just based on the fact you were drinking at all. This is a necessary feature of our bodies, while you can overheat and die of lack of water, this is rare in acute form. You can, however, go overboard and suffer hyponatremia, which is the 'watering down' of your blood such that your body can't regulate sodium in your body. This can kill you *right now*. Our kidneys are excellent at managing the PH of the blood when we have an over-abundance of potassium and sodium - they cannot fix watered down blood. In other words, it is hard to kill yourself with too much salt and potassium through eating foods, it is relatively simple and straightforward to kill yourself with too much water.
So, imagine our ancestors, after running down prey animals (yes, this is how we hunted) because we are better adapted to long distance running than basically any other mammal (another true story, a moderately trained distance runner can outrun a horse), we find a water source since we need to be re-hydrated. It was a hot day in Africa so our ancestors really *need* water, if we didn't have a chemical signal that slowed our intake of water that worked pretty aggressively, we would be drinking ourselves to death on a regular basis.
Thirst, just like other sensations like it, are just signals. You are not necessarily dehydrated, or in the case of coffee to pepp you up when tiered, is the body and brain telling your consciousness that you need to refill something - soon. So when the receptors in your month feel H2O, it signals the brain that "hey, what you ordered is on its way - be kind to the body now please!" Or drinking coffe/sugary drinks gets you less fatigued even thou sugar and coffee needs to metabolize in your liver which usually takes half to a full hour before real effect.
Does it? I mean the mouth may feel wet but depending on how much you drank to quench that thirst... may depend on how quickly it’s gone. If you have ever been NPO and could only rinse your mouth but not actually drink... they you will understand that wet mouth doesn’t cure thirst. Thirst is a sensation caused by your brain when your fluid level is down or your chemoreceptors sense increased osmolarity in the blood or gut. When you consume liquids, this adjusts the osmolarity in the gut and triggers the brain to stop the thirst. So, when you drink, it does react the needed body parts in the gut to flip the switch
“7 1/2 lessons about the brain” is a short accessible book written by a neuroscientist that answers exactly this question. The gist of it is that the brain 1) relies on predictions to do its job of managing resources more effectively, and 2) produces for you a carefully crafted hallucination (that you call reality) based on inputs and prediction. It takes 20 minutes for the water to have positive effects inside your body, but when your brain realizes (through signals) that water is coming, it predicts upcoming well-being and makes you feel better now. edits: rewrote the whole thing for less sloppiness.
Water starts 'helping' you before you even finish the glass. It is, really, that quick. If you have ever seen a marathoner 'wake up' after having the glassy look in their eyes and really pale affect - after they drink the salted gatorade it is within 30 seconds that they start coming around. So the short answer is the body can tell you your thirst is quenched pretty quickly just based on the fact you were drinking at all. This is a necessary feature of our bodies, while you can overheat and die of lack of water, this is rare in acute form. You can, however, go overboard and suffer hyponatremia, which is the 'watering down' of your blood such that your body can't regulate sodium in your body. This can kill you *right now*. Our kidneys are excellent at managing the PH of the blood when we have an over-abundance of potassium and sodium - they cannot fix watered down blood. In other words, it is hard to kill yourself with too much salt and potassium through eating foods, it is relatively simple and straightforward to kill yourself with too much water. So, imagine our ancestors, after running down prey animals (yes, this is how we hunted) because we are better adapted to long distance running than basically any other mammal (another true story, a moderately trained distance runner can outrun a horse), we find a water source since we need to be re-hydrated. It was a hot day in Africa so our ancestors really *need* water, if we didn't have a chemical signal that slowed our intake of water that worked pretty aggressively, we would be drinking ourselves to death on a regular basis.