Vegetative innervation of the esophagus. IV. Endings in the tela submucosa and tunica muscularis.

The osmium tetroxide-zinc iodide technique has been applied to the study of the tela submucosa and tunica muscularis in the esophagus of the cat and the rhesus monkey. Other than the classical terminal vegetative formation, three types of endings were found, classified as perifascicular, free and intramuscular. The comparative results between cat and rhesus monkey show differences in the distribution and number of such endings. A sensory functional significance is proposed and discussed.