This type of epithelium serves as a lining or covering and can be specialized for secretion and sometimes for absorption (e.g. the proximal convoluted tubules of the kidney). Although the height and shape of the cells may vary some, simple cuboidal epithelial cells are generally about as tall as they are wide, with a centrally located nucleus.

• The sample of kidney shows many examples of simple epithelia, from very thin simple squamous to rather high cuboidal. In the image to the right, we're looking at renal tubules lined with simple cuboidal epithelium.

• Trichrome staining in this kidney specimen allows you to see the basement membrane, which appears as a thin layer of blue-stained collagen surrounding the tubules. Compare the appearance of the basement membrane in the trichrome stained specimen to its appearance in this TEM image of the corneal epithelium.

• Next, examine this specimen of thyroid gland in which the glandular epithelium provides a nice example of cuboidal epithelium (Sample 1, trichrome stain).

Now for simple columnar epithelium.