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
Endometrial arteries blood to the endometrium but are also beneficial during pregnancy. When a female is pregnant a placenta develops. The baby receives blood, nutrients and oxygen via the umbilical cord which is attached to the placenta. Between the placenta and the myometrium are intervillous spaces where the endometrial arteries supply blood to. The placenta has villous trees which allow for blood to circulate and then be transported to the baby via the placenta. Endometrial arteries are divided into the common ones and the arteriovenous anastomosis. The common ones are arteries that are homologous to the arteries of the rest of the