This section from the submaxillary gland shows a large interlobular duct lined
with stratified columnar epithelium. Note that the cells of the basal
layer are cuboidal whereas the cells of the apical layer are columnar.
Note also: (1) the terminal web - the
dark line at the apex of each of the columnar cells, which marks the location
of the cytoskeleton in the apex of the cell; and (2) the terminal
bars - dark spots that punctuate the terminal web at the point
where two cells touch at their apical margins. The terminal bars mark the
location of the apical junctional complex by which the epithelial cells are
attached to one another.
