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

After endoscopic transurethral biopsies of normal human urinary bladde r, an extensive network of small initial lymphatic vessels was depicte d by means of light and electron microscopy. Using Eight microscopy, l ymphatic vessels were seen in the mucosa and submucosa and formed a co mplex network in the detrusor muscular coat. These lymphatics were cha racterized by an irregular and attenuated wall and increased in number and size from the superficial to the deeper region of the bladder. Ul trastructurally, the lymphatic wall was characterized by endothelial c ells joined together end-to-end or by complicated interdigitations. Of ten intercellular channels and gaps between two contiguous endothelial cells were present. A broad network of elastic and collagen fibers jo ined the lymphatic endothelial wall to the neighboring connective tiss ue. Nevertheless, as far as the fibrillar component was concerned, the vesical intramuscular lymphatic endothelial wall lacked elastic fiber s. These anatomic variations were examined in reference to lymph forma tion in an organ (the urinary bladder) which undergoes continual chang es in volume and pressure.