not sure if this is exactly what you wanted but its worth a shot

What is -- and what causes -- the marijuana "high"?

When you smoke a joint, the THC goes into your lungs, then into your heart which pumps it into your bloodstream which then takes it directly to your brain. When you smoke marijuana, it only takes a few minutes for the THC to get to your brain, whereas if you eat it, it would take a little longer because it has to pass through your digestive system first.

Once it's in your brain, the THC activates what are called 'receptors,' and gives you the feeling of being high. In short, marijuana changes the physical and chemical balance in your brain and this is what people refer to as a 'high'."
The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol). The membranes of certain nerve cells in the brain contain protein receptors that bind to THC. Once securely in place, THC kicks off a series of cellular reactions that ultimately lead to the high that users experience when they smoke marijuana. [...]

As THC enters the brain, it causes a user to feel euphoric ā?? or 'high' ā?? by acting in the brainā??s reward system, areas of the brain that respond to stimuli such as food and drink as well as most drugs of abuse. THC activates the reward system in the same way that nearly all drugs of abuse do, by stimulating brain cells to release the chemical dopamine.