Capillary embryonic development new capillaries are formed through vasculogenesis, the process of blood vessel formation that occurs through a "de novo" production of endothelial cells which then form vascular tubes. The term angiogenesis denotes the formation of new capillaries from pre-existing blood vessels and already present endothelium which divides. Blood flows from the heart through arteries, which branch and narrow into arterioles, and then branch further into capillaries where nutrients and wastes are exchanged. The capillaries then join and widen to become venules, which in turn widen and converge to become veins, which then return blood back to the heart through
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