[Physiology of the lymph vessel system]

Using an incomplete darkfield transillumination technique a prelymphatic network of tissue channels, connected with the initial lymphatics could be observed vitalmicroscopically in the mesentery of homeotherm animals. Furthermore, channels are found also paravascularly along the venules marked by a maximum of protein permeation in the capillary bed. Here exists a short way for the protein uptake by the prelymphatic system and initial lymphatics. This is important for the osmotically released movement of fluid into the lymphatic vessels. Supported by the connecting tissue fibres the prelymphatic system represents a preformed low resistance pathway for fluid movement convected to the initial lymphatics through the interstitial spaces.