Raynaud's disease results in brief periods of vasospasms. this disease affects blood supply to fingers and toes. it is also know
n to affect blood flow to lips, ears, nose and nipples. during what is called as "raynaud's attacks", the skin may turn white and then blue for a short time. which of these best describes why these symptoms occur?
The answer is excessive narrowing of blood vessels.
When exposed to the cold, our body tries to reduce its heat loss by tightening the arterioles under the skin (vasoconstriction). This mechanism increases the flow of blood into the deep veins and allows the body to maintain its internal temperature.
In people with Raynaud's disease, this reaction is excessive: the nerves that control the tightening of arterioles are hypersensitive and cause spasm, rather than normal vasoconstriction. When the spasm stops, the arterioles dilate again, restoring blood circulation.
