THE STRUCTURE OF NORMAL LARGE LYMPHATICS: HOW THIS DETERMINES THEIR PERMEABILITIES AND THEIR ABILITY TO TRANSPORT LYMPH

Abstract

It is well known that the structures of small lymphatics are very similar to those of small blood vessels (reviewed - 3, 4, 12). There are some differences, however, in that the lymphatics are more fragile, with tenous basement membranes, and endothelial intercellular junctions which sometimes lack zonulae adhaerentcs and usually lack zonulae occludentes. (The zonulae are regions where the plasma membranes of two cells come very close together and the cells appear to be more firmly united than elsewhere; the z. occludens is characterised by the outer membranous laminae actually seeming to fuse - 8.)