REFLEX CHANGES IN RESPIRATION INDUCED BY DISTENTION OF THE SMALL INTESTINE

The importance of distention in the various portions of the gastro-intestinal tract has been frequently stressed in experimental and clinical literature. Such interest has arisen largely from repeated demonstrations that the distention inevitably appearing on intestinal obstruction is the factor chiefly responsible for the grave physiologic disturbances associated with that condition.¹ Whether experimentally produced or resulting from actual pathologic conditions, excessive intraluminal pressure in the small intestine has been shown to produce a variety of local and general effects. Among the changes induced locally in the distended bowel segment are alterations in the motility,² the circulation,³ the absorption⁴ and the secretion.⁵ Changes of a more general character occurring in the entire volume of circulating blood include disturbance of the cell-plasma ratio⁶ and fluctuation of the level of nitrogenous substances in the blood.⁷ Certain other effects, apparently reflex responses to the stimulus of distention,