A quantitative study on the myenteric plexus of the distal end of the duodenum and the proximal part of the jejunum.
4 necropsy specimens taken from adult individuals were used in order to estimate the density of nerve cell bodies of the myenteric plexus in the last distal 5 cm of the duodenum and the proximal 5 cm of the jejunum (including the duodenojejunal flexure), that were subdivided into parts of approximately 1 cm and stained by Giemsa's method according to Barbosa (1970). Except for the first 2 parts, an increase of the neuron number was observed toward the duodenojejunal flexure, the greatest being at this point, and then decreasing progressively. The first duodenal parts, which corresponds approximately to the intersection of the mesenteric artery with the duodenum, showed the same neuron density as the duodenojejunal flexure. In this paper the 2 parts with higher neuron density were related to functional sphincteric zones, previously described.
D000328:Adult; D002452:Cell Count; D004386:Duodenum / Q000294:innervation*; D006801:Humans; D007583:Jejunum / Q000294:innervation*; D009197:Myenteric Plexus / Q000166:cytology*; D009474:Neurons / Q000166:cytology