The structure of an epithelial cell from the small intestine as seen with an optical microscope.

Epithelial cells make up a lot of tissue in the human body- including that of the small intestine. They are eukaryotic cells (nucleus and a variety of organelles) which specialise in absorption and secretion.

With a light (optical) microscope the following can be seen:

Extra reading: http://www.bio.davidson.edu/people/kabernd/BerndCV/Lab/EpithelialInfoWeb/