Raynaud phenomenon is a vessel abnormality caused by overactivity of smooth muscle in the wall of arteries, causing contractions, or vasospasms, of the small vessels that supply blood to the arms, legs, hands, and feet. Raynaud phenomenon is usually diagnosed in persons younger than 40 years and occurs 5 times more frequently in women than in men.
Circulatory System
Circulatory System, or cardiovascular system, in humans, the combined function of the heart, blood, and blood vessels to transport oxygen and nutrients to organs and tissues throughout the body and carry away waste products. Among its vital functions, the circulatory system increases the flow of blood to meet increased energy demands during exercise and regulates body temperature.