A student was given a sample of tissue. He observes and concludes the following characters.

1. The cells are composed of a single layer of tall and slender cells.
2. Their nuclei are located at the base.
3. Free surface may have microvilli.
4. It is found in the lining of stomach and intestine
5. They help in secretion and absorption.

Based on the above features identify the epithelium.

Columnar epithelium is an epithelium consisting of one or more layers of elongated cells of cylindrical or prismatic shape. Columnar epithelial cells resemble elongated boxes. They have oval nuclei that usually are situated in the lower part of the cell. The cells are closely joined together and rest on a basement membrane, known as the basal lamina. Some cells have tiny hair-like structures known as cilia on their upper surfaces. These tiny fronds beat in unison to waft particles across the cell surface. Columnar cells with cilia can be found in the respiratory tracts. Other cells have minute finger-like projections called microvilli. These help to increase the surface area available for absorption and can be found lining the intestines.