Observations on the submucous plexus and mucosal arteries of the dog's stomach and first part of the duodenum.

Arteriolar patterns of the submucous plexus were studied in all areas of the dog's stomach and in the first inch of the duodenum. There appeared to be no poverty of plexus, although in some cases the vessels were somewhat smaller in the pyloric part of the lesser curvature than elsewhere. Mucosal arteries arose from the plexus, and none appeared to have an extramural origin. In man, on the other hand, there is a poverty of the submucous plexus in the 'ulcer region', i.e. in the incisural region of the lesser curvature and in the first inch of the duodenum, associated in some cases with mucosal end arteries of extramural origin. The absence of these features in the dog, which does not suffer from spontaneous chronic ulceration, lends further support to the view that they play a role in the aetiology of the disease in man.