The American Journal of Physiology

The movements of the intestinal villi in living animals were first described by Gruby and Delafond (1). Since the appearance of their report in 1843, contributions to this subject have appeared sporadically. Among those dealing to a large extent with the movements of the villi and giving little or no consideration to the activities of larger masses of the muscularis mucosae are contributions by Bruecke (2), Hambleton (3), King and Arnold (4), Verzhr and MacDougall (5), Kokas (6), Ludany and Jourdan (7), and Wells and Johnson (8). The subject matter in these treatises centers largely around descriptions of the movements of the villi, the nature of the stimulus or stimuli, and an attempt to correlate the activity of the villi with the processes of secretion and absorption. In a smaller group of reports primary attention has been given to the activities of larger masses of the muscularis mucosae. Papers by Exner (9), Gunn and Underhill (lo), King and Church (11)) Thorell (12)) and Forssell (13), have dealt with various aspects of this subject. There is a fairly close agreement among the different writers in their descriptions of the types of contractions executed by the muscularis mucosae. The more fundamental problems, however, dealing with the nature of the normal physiological stimulus or stimuli, the myogenic or neurogenic origin of the contractions, the physiological function of the contractions, and the role of the nervous mechanisms present have remained unsettled. With respect to innervation there is general agreement that the sympathetic system supplies excitatory fibres to the muscularis mucosae of the small intestine, rather than inhibitory as in the case of the outer musculature. tion of the parasympathetics has not been so well worked out. The funcThorell (12) found that as a general rule the muscularis mucosae of the stomach was caused to contract by acetylcholine although in some animals this reaction was obtained only from certain regions of this organ. King and Church (11) noted the contractile effect of pilocarpine on the muscularis mucosae of the dog’s small intes-