Interessant bilde som viser hvordan sympaticus nerver stenger «shunts» i huden for å øke blodsirkulasjon til huden og avgi varme, mens sensoriske nerver åpner «shunts» slik at blodsirkulasjonen til huden minker og vi kan bevare varme. I fibromyalgi har forskere funnet at sensoriske nerver holder «shunts» åpne slik at blodsirkulasjonen i huden minker, dette gir kalde hender og bidrar til smerte. Nevner at hender og føtter er et «reservoir» av blod som kan påvirke blodsirkulasjonen i hele resten av kroppen.

http://medicalxpress.com/news/2013-06-fibromyalgia.html

This schematic illustrates the organization of blood vessels and the regulation of blood flow (arrows) in the palm of the hands. Arteriole-venule shunts are small muscular valves that connect directly between an arteriole and a venule to bypass the capillaries. Arrows indicate the direction of blood flow. As shown on the left, in order to radiate heat from our skin when we are hot, activation of the sympathetic nerve fibers close the shunts so that oxygenated blood (red arrows) in the arterioles is forced into the capillaries and deoxygenated (blue arrows) blood returns to the venules. As shown to the right, in order to conserve heat when we are cold, activation of sensory nerve fibers dilate the shunts and the blood bypasses the capillaries. Fibromyalgia patients were found to have an excessive amount of sensory fibers around the shunts.

Dr. Rice continued, «We previously thought that these nerve endings were only involved in regulating blood flow at a subconscious level, yet here we had evidencs that the blood vessel endings could also contribute to our conscious sense of touch… and also pain.»

As Dr. Rice describes their function, «We are all taught that oxygenated blood flows from arterioles to capillaries, which then convey the deoxygenated blood to the venules. The AV shunts in the hand are unique in that they create a bypass of the capillary bed for the major purpose of regulating body temperature.»

«In addition to involvement in temperature regulation, an enormous proportion of our blood flow normally goes to our hands and feet. Far more than is needed for their metabolism» noted Dr. Rice. «As such, the hands and the feet act as a reservoir from which blood flow can be diverted to other tissues of the body, such as muscles when we begin to exercise. Therefore, the pathology discovered among these shunts in the hands could be interfering with blood flow to the muscles throughout the body. This mismanaged blood flow could be the source of muscular pain and achiness, and the sense of fatigue which are thought to be due to a build-up of lactic acid and low levels of inflammation fibromyalgia patients. This, in turn, could contribute to the hyperactvity in the brain.»