Simple columnar epithelia are specialized for absorption. As their name implies, these cells are taller than they are wide, and their nuclei are usually located closer to the basal surface.

• This type of epithelium lines the gall bladder (H&E stained sample and a trichrome stained sample) and the projecting villi in the small intestine.

• The apical surfaces of the simple columnar epithelial cells in the small intestine are covered by microvilli, which provide a larger surface for absorption (seen below in LM and EM images). Many cells have microvilli at their apical surfaces, but they are especially well developed in the small intestine.

• In this slide, the glycocalyx on the microvilli is stained "magenta" by the PAS reaction, demonstrating the microvilli collectively as the brush or striated border. The glycocalyx is also visible in the TEM image of intestinal epithelium seen above in the far right panel.
• In these two slides of small bowel, ileum stained with trichrome and jejunum stained with H&E, study the brush border again and examine the terminal web, the network of actin filaments in the cytoplasm just below the microvilli.
• Some cells of the simple columnar epithelium, called goblet cells (arrow in left panel above), are specialized for secretion of mucus rather than absorption. Take a look at this PAS stained slide to see if you can locate these unicellular goblet shaped glands. PAS stains the mucin granules that fill the cytoplasm, demonstrating the overall size and shape of these cells.
   

Here are some interesting facts about epithelial cells.