The mammalian lacteal: its histological structure in relation to its physiological properties

Abstract

One of us (H. W. F.) (7, 8) has already noted that the mesenteric lacteals contract on appropriate stimulation in a number of animals. He also observed in the guinea-pig and the rat that the vessels were rhythmically contractile. In the latter species the nuclei of circular muscle fibres in the lacteal wall could be seen in the living condition. The difficulties, however, of making out the part played by smooth muscle cells and nuclei in such contractions are very great in the living preparation. It was, therefore, resolved to supplement these observations on the living mesentery by others on fixed and stained material. In some cases the excised lacteal had actually been observed to contract in the living mesentery. The mesenteric lacteals of the cat have been taken as a type, and special attention has been paid to the distribution of smooth muscle fibres in the lymphatics in the various species studied.