Quote from charli_apple
parasympathetic= rest and digest
sympathetic=fight or flight
I say to myself that the sympathetic system has sympathy for me when I need to either fight or flight.
Think about what happens when you need to fight or flight...your heart beats faster so u can get more blood to your body, your bronchioles dilate to allow for passages oxygen through your body. Your blood vessels near skin dilate: think about how you feel cool and get goosebumps when you are scared or afraid.
In the opposite manner, the parasympathetic system is all about resting and digesting. The word choline means rest, so cholinergic meds assist this system.
When I think of my medications, (I'm taking pharm right now, also) I visualize the scene in pulp fiction where the woman takes the depressant drug, gets a cool high then passes out. But the guy comes in, gives her a shot of l, I'm thinking adrenalin or epinephrine or something that works on sympathetic system and she wakes up startled.
Sympathetic system does the following:
Taken from http://curiosity.discovery.com/quest...ns-when-scared
Increase in heart rate and blood pressure
Constriction of veins in the skin, which causes the chilly sensation often associated with fear
Increased blood glucose
Tensing of muscles and goose bumps
Relaxation of smooth muscles
Shutting down of nonessential systems such as digestion and the immune system
Difficulty concentrating on small tasks
Once the threat diminishes, the body releases the hormone cortisol to calm itself back down to normal. The entire fight-or-flight cycle is part of a defense mechanism that has developed over thousands of years. Without it, one of your direct ancestors may not have been able to defend themselves or escape from predators or enemies.