Circulatory system that were cut during life bleed. He ascribed the fact to the phenomenon that air escaping from an artery is replaced with blood that entered by very small vessels between veins and arteries. Thus he apparently postulated capillaries but with reversed flow of blood. In 2nd century AD Rome, the Greek physician Galen knew that blood vessels carried blood and identified venous (dark red) and arterial (brighter and thinner) blood, each with distinct and separate functions. Growth and energy were derived from venous blood created in the liver from chyle, while arterial blood gave vitality by containing pneuma (air) and
Urinary bladder mediate bladder diseases such as overactive bladder. The bladder is supplied by the vesical arteries and drained by the vesical veins. The superior vesical artery supplies blood to the upper part of the bladder. The lower part of the bladder is supplied by the inferior vesical artery in males and by the vaginal artery in females, both of which are branches of the internal iliac arteries. In females, the uterine arteries provides additional blood supply. Venous drainage begins in a network of small vessels on the lateral and posterior surfaces of the bladder, which coalesce and pass backwards along the