Up until this point we have talked about discrete anatomic regions of the brain. The autonomic nervous system is diffusely organized and present throughout all layers of the brain and widely distributed throughout the body. We earlier mentioned subconscious spinal cord information and much of the autonomic nervous system handles its job without thought. The autonomic nervous system helps to regulate temperature, blood pressure, pulse, digestion and excretion. With all you have to worry about it is nice that these vital functions are taken care of without you having to pay attention.
Every once in awhile the autonomic nervous system lets you know it's there.
Just as in our earlier discussion of the hypothalamus, it is important to recognize that these signals from the autonomic nervous system are internal environment inputs. They can affect your behavior and sense of well-being but are not essentially "you." When you are in a stressful situation which could be physical, such as standing on the high board while all your friends watch you attempt a new movement, your autonomic nervous system will raise your heart rate and you may find your heart "pounding in your chest".
A stressful situation may be mental, such as being asked to stand in front of the class and recite a poem you barely know and your autonomic nervous system acts up by raising your temperature and trying to cool you down by having you perspire profusely. The stressful situation may be social, such as trying to ask someone to dance with you and just as they agree and take your hand you find your palms cold and clammy. These are all part of the "fight or flight" response. An all too common behavioral component of this response is anger. Just be aware of where this is coming from.
I wish I could tell you how to control your autonomic nervous system but that is too big a secret. I can tell you that all of those embarrassing situations have happened to everyone and they are not unique to you. "Butterflies in the stomach" will not go away since it is your autonomic nervous system's way of telling you that you are under stress. Remember your earlier lessons. Breath deep and slowly, stand tall, smile and make the best of it.