Fine structure of the lamina muscularis mucosae

Abstract

Phase contrast and electron microscopic studies of the lamina muscularis mucosae of the mouse intestine were carried out in order to elucidate the cytologic detail of the cells and their orientation. This smooth muscle element was found to be a three-dimensional network of flattened cells with elongate processes, the processes of each cell contacting those of its neighbors. The lower limit of the net is a more densely packed layer of nonpolarized flattened cells underlying the bases of the glands of Lieberkuhn. These tubular intestinal glands are enmeshed in the net of muscle cells. It is suggested that the muscularis mucosae serves a secretion-moving function, expressing the products of the intestinal glands.