What is a property of epithelial tissue?

There are two structurally and funtionally different surfaces in epithelial tissue.

Explanation:

The outer covering of organs and blood vessels is lined by epithelial cells. These cells also line the inner surface of many cavities in the body.

Glands are formed of epithelial tissue and divided how they secrete their hormones (Exocrine and Endocrine gland). The cells in epithelial tissue are tightly packed. One side of cells is free that is not in contact with other cells (outer covering).