The Autonomic nervous System
Blood vessel activity is controlled by the autonomic nervous system, which in turn is controlled by lower levels of the brain (medulla oblongata and lower brainstem). The autonomic nervous system (ANS) is designed to work silently and independently of the conscious brain. Our conscious brains have enough to think about in our dealings with work, people, chores, responsibilities and life in general. Imagine if we actually had to direct how to digest our food, control blood flow throughout our body, synchronize our breathing, adjust how much we sweat, coordinate the muscles when chewing, swallowing and working, and constantly adjusting the lens of our eyes when we focus and accommodate for light -- and a thousand other simultaneous functions. The ANS handles these functions for us, maintaining physiological balance twenty-four/seven.
The ANS consists of two systems: the sympathetic and parasympathetic nervous systems. These two operating systems act independently as they balance the functions of the ANS. In general, the sympathetic system is the activating system, whereas the parasympathetic system is the resting and restorative system. These two systems play a distinct role in the symptoms of EM.
The Sympathetic System
Characteristically, the sympathetic nervous system turns on between 5 and 7 in the morning. The sympathetic system readies the body for daily activity. From the moment we rise, we become bodies in motion, grooming and then working until late afternoon. To accomplish this, the sympathetic nervous system increases the heart rate, breathing rate, cortisol levels -- and tightens the blood vessels. This tightening is not noticeable to most people, nor was it to us before we developed EM. But now, with EM, we can readily see the difference when the sympathetic nervous system activates. Except in severe cases, our EM improves.
The Parasympathetic System
As the day wears on, the sympathetic tone gradually winds down, relinquishing its control to the parasympathetic system. The heart rate drops, the breathing rate slows, and the blood vessels begin to open. These changes are subtle and usually go unnoticed in healthy people. Yet as these changes occur, people with EM readily notice that their symptoms are worsening. In healthy people, the vasodilation that occurs during the parasympathetic mode is usually small, but in us the difference can be huge. In EM, the vascular system overreacts to any degree of vasodilation. EM is a condition in which the normal control mechanism of blood vessel activity is severely damaged. At mild temperatures such as 60 or 70 degrees, our blood vessels open as widely as if it were 110 degrees. Similarly, the slight vasodilation caused by parasympathetic activation is huge in us.