Quad Venti, Skim, No Whip, Peppermint Mocha

I am literally falling asleep at work today - my eyes are watering and I can barely hold my head up at my desk. That made me wants to talk about caffeine (aka: trimethylxanthine).

We all know our love for caffeine. It has gotten us through some hard times. Not one of us would have graduated from college without it. It is America’s favorite and most popular drug. And it’s fitting to call it a drug because it works the same way as cocaine and heroin do in the brain.

First you need a basic lesson on what happens when you are tired. In addition to lots of other things going on all over your body, adenosine begins circulating and binding to receptors in your brain. Once adenosine binds, nerve cells start to slow activity and blood vessels dilate to let more oxygen into your brain. That is why you start to feel tired.

It’s a whole other story when caffeine is present.

To a nerve cell, caffeine looks an awful lot like adenosine. When it is in your brain it too can bind to the adenosine receptors. Caffeine actually binds better to the receptors than adenosine does, so before your body knows it, all of the receptors have caffeine bound to them. Although they look alike, they do not act alike. Caffeine actually causes an increase in nerve activity and also causes the blood vessels to constrict (a good reason to have caffeine in headache medicine). With all this activity, your body gets a little confused and thinks it needs to respond. The pituitary gland starts producing lots and lots of adrenaline. I’m sure you know enough about adrenaline to know that the body is not tired anymore.

Adrenaline causes your body to switch into a “fight or flight” state (sympathetic neuronal response). Your heart speeds up, blood pressure rises and you start breathing faster. You liver also starts releasing sugars into your body for extra energy. Another fun thing caffeine does is increase the level of dopamine in your body (just like coke and heroine). This is the chemical that makes you happy. Dopamine is probably why people are addicted to caffeine.

Eventually the caffeine wears off and the adenosine is able to start binding again - making you ready to fall back asleep. I heart caffeine so I am going to skip the short/long-term effects of it. Just remember that it is a drug – don’t use it too much.