Vein cells called tunica intima. The precise location of veins varies much more from person to person than that of arteries. Veins serve to return blood from organs to the heart. Veins are also called "capacitance vessels" because most of the blood volume (60%) is contained within veins. In systemic circulation oxygenated blood is pumped by the left ventricle through the arteries to the muscles and organs of the body, where its nutrients and gases are exchanged at capillaries. After taking up cellular waste and carbon dioxide in capillaries, blood is channeled through vessels that converge with one another to form
Vagina and the internal pudendal artery, all branches of the internal iliac artery. Three groups of lymphatic vessels accompany these arteries; the upper group accompanies the vaginal branches of the uterine artery; a middle group accompanies the vaginal arteries; and the lower group, draining lymph from the area outside the hymen, drain to the inguinal lymph nodes. Ninety-five percent of the lymphatic channels of the vagina are within 3 mm of the surface of the vagina. Two main veins drain blood from the vagina, one on the left and one on the right. These form a network of smaller veins, the