Simple columnar epithelium is a type of epithelial tissue consisting of a single layer of tall, elongated cells that are taller than they are wide. The cells have oval-shaped nuclei usually located near the base. This epithelium is primarily involved in absorption and secretion functions. There are two main types of simple columnar epithelium:
- Non-ciliated simple columnar epithelium has microvilli on the apical surface to increase surface area for absorption and includes goblet cells that secrete mucus. It lines most of the digestive tract such as the stomach and intestines.
- Ciliated simple columnar epithelium has cilia on the apical surface that help move mucus and other substances. It is found in places like the uterine tubes and parts of the respiratory tract.
The cells are tightly packed, attached to the basement membrane, and have many organelles to support secretion and absorption. Goblet cells interspersed within the epithelium secrete mucus that protects and lubricates the lining where this tissue is found.