Collan, Y. & Kalima, T. V. 1970. The Lymphatic Pump of the Intestinal Villus of the Rat. Scand. J. Gastroent. 5, 187-196.

The structure of the intestinal villus and its lymphatic was studied electron-microscopically. There is in the lamina propria of the villus a network of collagen fibres to which the endothelial cells of the lymphatic, the capillary net of the villus, fibroblasts, muscle cells, and nerve fibres are attached. The immediate proximity of the lymphatic and muscle cells can be explained by considering the constricting activity of the villus a lymphatic pump. The inlet valves between the endothelial cells are equally profuse in both the transverse and longitudinal sections of the lymphatic.