[The functional colonic sphincter in the rat].

In the proximal colon of the rat typically aligned mucosal folds are found which are displaceable but not erasable (transposable folds). The spatial arrangement of these folds produces a tierlike structure in this section of the intestine by the development of functional ring valves, which allow the flow of food in an oral to anal direction. The basis of these mucosal folds is formed by a vascular apparatus which is peculiar to them. The functional unit of the folds and their vascular apparatus is referred to as the 'angioplicate lock system'. A reversal of operation of even the smallest sections of this lock system inevitably produces a fatal ileus.