[Electron microscopy of the lymphatics of the ureter (author's transl)]

Microvasculature of the mouse and human ureter was investigated by light and electron microscopy. Lymph vessels were only seen in the adventitial layer of the mouse ureter. Only one lymph capillary could be demonstrated in the submucosal and muscularis layer of the human ureter. Fenestrated blood capillaries were arranged just beneath the transitional epithelium. Numerous thin-walled postcapillary venules characterized by endothelial channels and fenestrations were seen in the adventitial layer. Apparently, a widespread ureteral lymphatic system is not necessary, since protein rich extracellular fluid can be reabsorbed by venous blood capillaries.