Scanning electron, light, and transmission electron microscopy of intestine of gnotobiotic calf.

Adjacent areas of upper, middle, and lower parts of the small intestine and spiral colon from a 48-hour-old gnotobiotic calf were compared by scanning electron microscopy (SEM), light microscopy (LM), and transmission electron microscopy (TEM). As visualized by all 3 methods, small intestinal histologic features, except for apical location of villous epithelial cell nuclei in sections of upper and middle parts of small intestine, were similar to those described for other species. The colonic surface visualized by SEM was composed of flattened ridges separated by furrows into which opened the crypts of Lieberkühn. The epithelial surfaces of the ridges and the furrows had an extensive microvillous covering and scattered goblet cell openings.