system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: How is thirst satisfied almost instantly after drinking something, even though it takes the body some time to absorb the liquid?
gpt
It takes very little time to absorb water.   You absorb it right from the time it hits your stomach, unlike a lot of food which has to pass through to the small intestine before you can start to absorb it.  It’s also very easy to absorb it.   You have special holes in your stomach and small intestine for water to just mosey through, unlike most things which need to be frog-marched through by an escort.   This makes water absorption very, very fast. 

As soon as you start absorbing water, your blood volume increases because that is where water goes.  Increasing your blood volume increases your blood pressure.  Increasing your blood pressure tells special sensors in your blood vessels that you are no longer dehydrated.  This message gets sent to your brain neurologically, and your brain stops releasing the “you are thirsty” hormone.