What is the name of the chemical that the body uses to communicate with itself?

Question

For instance, your stomach telling your large intestine that it's ready to pass along the nutrients to the next stage in the digestion process.

Or how your eye tells your brain what you're seeing.

I can't quite remember the name of the chemical, but I think it starts with an "H".

...It's not homogen is it? =P

Help!

Answer 1

Hormones are the chemical messengers your body uses to control certain processes, such as digestion.

Your eye communicates with the brain via nerve impulses and not hormones.

- Well the stomach - intestine part it definitly hormones and nerve impulses.

But this thing with the eye I've never heard of this chemical, and i've studied the eye till A level, so unless its a higher level thing, i dont think there is such a chemial and i really wouldn't go by "The Eye" =P

Weird visions would really be related to the brain, the eyes only see's whats there, but our brain can make us think/see otherwise. So more likely the chemical, if it exisit lol, would be inside the brain.