THE LYMPHATIC VESSELS AND THEIR RELATIONSHIP TO LYMPH FORMATION IN THE HUMAN URINARY BLADDER

Abstract

After endoscopic transurethral biopsies of normal human urinary bladder, anextensive network of small initial lymphatic vessels was depicted by means of light andelectron microscopy. Using light microscopy, lymphatic vessels were seen in the mucosaand submucosa and formed a complex network in the detrusor muscular coat. Theselymphatics were characterized by an irregular and attenuated wall and increased innumber and size from the superficial to the deeper region of the bladder.Ultrastructurally, the lymphatic wall was characterized by endothelial cells joinedtogether end-to-end or by complicated interdigitations. Often intercellular channels andgaps between two contiguous endothelial cells were present. A broad network of elasticand collagen fibers joined the lymphatic endothelial wall to the neighboring connectivetissue. Nevertheless, as far as the fibrillar component was concerned, the vesicalintramuscular lymphatic endothelial wall lacked elastic fibers. These anatomicvariations were examined in reference to lymph formation in an organ (the urinarybladder) which undergoes continual changes in volume and pressure.