What shapes can epithelial cells have on the surface of epithelia?

What shapes can epithelial cells have on the surface of epithelia?

• A. All of the above
• B. Squamous
• C. Columnar
• D. Cuboidal

Answer: (A)

Epithelial surfaces come in different shapes to suit their roles, so you’ll find flat, square, and tall cells at the surface depending on the tissue. Flat squamous cells are common where diffusion or slick surfaces are needed, such as in the lining of alveoli or blood vessels. Cube-shaped cuboidal cells appear where absorption and secretion are important, like in many kidney tubules and glands. Tall columnar cells are typical where there's active absorption or secretion, such as in the intestinal lining. Because all three shapes occur as surface cell types in different epithelia, the option that includes all of them is the best choice. Keep in mind that some epithelia are stratified, and the outermost layer can be squamous, cuboidal, or columnar, and there are transitional epithelia that can change shape with stretch.

Epithelial surfaces come in different shapes to suit their roles, so you’ll find flat, square, and tall cells at the surface depending on the tissue. Flat squamous cells are common where diffusion or slick surfaces are needed, such as in the lining of alveoli or blood vessels. Cube-shaped cuboidal cells appear where absorption and secretion are important, like in many kidney tubules and glands. Tall columnar cells are typical where there's active absorption or secretion, such as in the intestinal lining. Because all three shapes occur as surface cell types in different epithelia, the option that includes all of them is the best choice. Keep in mind that some epithelia are stratified, and the outermost layer can be squamous, cuboidal, or columnar, and there are transitional epithelia that can change shape with stretch.