It makes sense that bad tastes and smells trigger our gag reflex, but what in the brain triggers gag reflexes upon seeing something bad?

Question

The sight of certain things or images has made me throw up before and I don’t understand how eyesight can trigger the gag reflex.

In: Biology

Answer 1

It is an evolutionary trick that is related to disgust. Our brain is wired to be disgusted around things that can poison or infect us. When you see (or smell) something like poop, or a dead animal, or rotten food, it triggers this reaction as sort of a reminder that we shouldn’t eat that or be around that because it can make us sick. Or if you try to eat it, your body (and evolutionary brain) is screaming at you “NO! that’s bad!” – and you cant eat it or it makes you throw up.