Fig. 5. Light microscopy and transmission electron microscopy of the duodenal mucosa epithelium of digesting caimans. Enterocytes are filled with lipid droplets and arranged as a single layered high prismatic epithelium. (A) Low power light micrograph of a villus showing the typical arrangement of lipid filled enterocytes with a well developed brush border and a large capillary in the connective tissue core of the villus. (B) High power light micrograph of the mucosa epithelium. Note the dense layer of lyphocytes and a large mast cell below the epithelium. (C) High power light micrograph of the tip of a villus with necrotic cells. Necrotic cells are enlarged as compared with healthy enterocytes and show different degrees of lysis of the cell membranes as well as the nuclei. (D) Low power transmission electron micrograph. Note the dense distribution of mitochondria and lipid droplets. (E) High power transmission electron micrograph of the brush border with pinocytotic pits at the basis of microvilli (arrows). bb, brush border; c, capillary; eec, enteroendocrine cell; iel, intraepithelial lymphocyte; l, lymphocytes; la, lacteal; lp, lipid droplet; m, mitochondria; mc, mast cell; mv, microvilli; n, nucleus of enterocytes; ne, necrotic enterocytes.