Microvascular patterns of the hard palatine mucosa in the Japanese monkey (Macaca fuscata)

Abstract

Detailed investigations were made of the microvasculature of the mucous membrane, especially the transverse palatine plicae, of the hard palate of the Japanese monkey (Macaca fuscata)utilizing the plastic injection method. The microvascular patterns obtained were compared with those of the cat and other mammals. The incisive papilla was located at the anterior end of the median line of the hard palate, and seven or eight transverse palatine plicae were observed symmetrically from this papilla posteriorly at similar intervals. Each plica arched bilaterally in a wide M. The heights of the plicae decreased gradually at their lateral ends. The whole palate was supplied by two arteries. The minor palatine artery supplied the soft palate and the major palatine passed forwards to supply the hard palate, sending off numerous, medial and lateral branches. The plical branches diverging from both these branches formed a primary arterial network (submucous arterial network), and arterioles diverging superiorly from this network formed a second arterial network (arterial network in the lamina propria). Fine twigs diverging from the latter network formed a subepithelial capillary network immediately beneath the epithelium. Capillary loops sprouted out of the above network in the lamina propria. The descending crus of each loop drained via the subepithelial capillary network of the venous side into a venous network located in the same layer as the arterial network. These vessels finally drained into the submucous venous network (palatine venous plexus). In conclusion, the transverse palatine plicae in M. fuscata were formed from a thickening or eminence of the lamina propria, as opposed to the submucous tissue in the cat. Accordingly, the presence of such submucous tissue has been not observed in M. fuscata except in a limited area of the hard palate. The microvascular patterns of the hard palate of M. fuscata were similar to those of the cat.