Lymphatic Architecture of Suncus Murinus (House Musk Shrew) Palatum

The architecture of craniocervical lymphatic vessels in rodents has been examined previously. In the present study, we evaluated the distribution of collecting lymphatic vessels in the palate of Suncus, which is known to retain the prototype of placental mammals and is more similar to humans in terms of jaw bone morphology when compared with rodents. Three-dimensional reconstructed images of the Suncus palatum revealed that the collecting lymphatic vessels were connected to each other via smaller branches, and ran in an antero-posterior direction in the periosteum. The vessels entered the pair of posterior palatine foramina located near the fourth premolar or the first molar bilaterally, coursed through the posterior palatine canals, and reached the pterygopalatine fossa positioned posteriorly in the palate. The collecting lymphatic vessels changed directions from medial to superior to lateral while wrapping around arteries during their course, perhaps to enable the smooth transition from the palate to the deep cervical node. Inefficient lymphatic flow in humans is attributed to the superior location of the pterygopalatine fossa in the palate when compared with its location in the Suncus.