ï»¿ Microscopic Appearance of Simple Columnar Epithelium Simple columnar epithelial tissue consists of a single layer of tall cells that resemble a row of pillars. Each cell is tall and column-shaped, and may contain an elongated nucleus. The cells form a single row where the neighboring cells attach to each other. The apical surface of an epithelial cell contacts the lumen, a hollow cavity inside the body. The opposite border of each cell, also known as the basal surface, contacts a basement membrane that separates the epithelium from the underlying connective tissue. Simple columnar epithelium functions in absorption, and or secretion. Simple columnar epithelium sometimes contains specialized columnar cells called goblet cells. Goblet cells secrete mucous into the lumen. Simple columnar epithelium lines a large portion of the gastrointestinal tract. So, let's take a look at some examples. This is simple columnar epithelium lining the stomach. This is the lining of the small intestine. This is the lining of the large intestine. Notice how the goblet cells stain red in this preparation. In some areas, such as small bronchioles, simple columnar epithelia contain cilia projecting into the lumen. Cilia are tiny cellular extensions that move a substance, such as mucous, in one direction. Cilia are also found lining the uterine tubes to help move an egg cell through the uterine tube to the uterus. Let's finish by reviewing the microscopic appearance of simple columnar epithelium. Single layer of tall cells found in the stomach, small intestine, large intestine, bronchiole, and uterine tube.