Question

Identify the function of columnar epithelium
A. Selective transport of substances
B. Prevention of wearing of organs
C. Secretion of digestive juice
D. Reabsorption of useful materials from urine

Answer 1

Hint: Tissues are made up of a single layer of long epithelial cells that are commonly observed in several regions of the alimentary canal. It can be identified by the number of layers and the shape of the upper layers.

Complete answer: The columnar epithelial cells have four times their height to their width. They can be simple or unilayered and stratified or multi-layered. They are arranged like a pillar and are usually tall. The columnar epithelium is commonly found in various regions of the alimentary canal such as the stomach, small intestine, etc. They form the inner ring of the small intestine. It helps in the absorption of water and nutrients. It is commonly present in regions where absorption and secretion are important features. They also act as an impermeable barrier against any bacteria that can be ingested and is permeable to any necessary ions. This is an important function in the colon of the large intestine. They also help in protection against any wearing and tearing.
Hence, the correct option is C-Secretion of digestive juice.

Note: In the columnar epithelium of the small intestine, certain cells secrete mucus, digestive enzymes, and hormones. It has numerous tubular gastric glands that open to the surface of mucosa through tiny holes known as gastric pits. Columnar epithelial cells are also found in the female reproductive system and the nasal passage.