Pavlov's Pouch

Pavlov's pouch [′pav‚läfs ‚pau̇ch]

(physiology)

A small portion of stomach, completely separated from the main stomach, but retaining its vagal nerve branches, which communicates with the exterior; used in the long-term investigation of gastric secretion, and particularly in the study of conditioned reflexes.

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Pavlov’s Pouch 

(Russian, isolated pouch), a pouch artificially created for experimental purposes from part of the stomach of an experimental animal.

The first isolated pouch was created by R. Klemensevich in 1875 from the pyloric part of a stomach. In 1879, R. Heidenhain proposed a modified isolated pouch made from the fundal portion of the stomach in order to study the principles of secretion of the fundal glands. Heidenhain’s pouch was a cul-de-sac, with a fistula leading to a skin wound, made from a section of the greater curvature of the stomach by completely cutting through its wall, including severance of the vagus. By creating an isolated pouch pure gastric juice could be obtained since ingested food did not enter the isolated pouch. However, as a result of denervation, juice secretion in Heidenhain’s pouch did not correspond to secretion in the stomach.

In 1894, I.P. Pavlov worked out a method of obtaining an isolated pouch without these defects. According to Pavlov’s method, longitudinal incisions are made, running parallel to the nerve fibers. The stomach is separated from the isolated pouch only by a layer of mucosa, leaving between them a “bridge” of serous and muscle layers, into whose mass pass branches of the vagus and blood vessels. Pavlov’s method has the advantage of preserving the innervation of the isolated pouch, thereby permitting study of the mechanisms of the nervous regulation of gastric secretion. Various modifications of Pavlov’s pouch have been proposed for the study of gastric digestion, of food selection and consumption, and of the action of medicinal substances.

G. I. KOSITSKII and I. N. D’IAKONOVA