Cytology 14

This photomicrograph was taken of a portion of the small intestine as seen in a thin plastic section at nearly the limiting resolution of the light microscope. A number of features of the simple columnar epithelium lining the intestine are indicated. Arrows A and B both point to goblet cells: A indicates the mucous granules of the apical cytoplasm while B indicates the narrow, oval, relatively dark nucleus typically found in the basal cytoplasm. G is placed in the pale supranuclear cytoplasm of the tall columnar absorptive cells, reflecting the location of the Golgi apparatus. The arrow MV indicates the microvillous ("brush") border of these cells, while the thin pale zone immediately under the microvilli is the location of the terminal web. The right-pointing arrowheads mark the location of very small dark spots (sometimes called terminal bars) thought to reflect the "dimpling" of the epithelium by the occluding junction portions of the junctional complexes that hold these epithelial cells together.

Slide A-14, 63X objective