What is the primary function of epithelial tissue?

The primary function of epithelial tissue is to cover and protect surfaces. Epithelial tissue forms the linings and coverings of both internal and external surfaces of the body. It serves as a barrier that protects underlying structures from physical damage, pathogens, and dehydration. Additionally, epithelial tissue is involved in absorption, secretion, and sensation, contributing to the overall functionality of organs and systems. Its unique structure, characterized by tightly packed cells with minimal extracellular matrix, allows for selective permeability, ensuring that necessary substances can pass while keeping harmful agents out. This essential role in protection and covering differentiates epithelial tissue from other types in the body, which have distinct functions, such as supporting and binding tissues or facilitating movement.