What role does epithelial tissue serve in the body?

Epithelial tissue serves the essential role of covering and protecting the body's surfaces, including both the external skin and the internal linings of organs and cavities. This tissue acts as a barrier, providing protection against mechanical injury, pathogens, and fluid loss. It also plays a critical role in absorption, secretion, and sensation, allowing the body to interact effectively with the environment. The characteristics of epithelial tissues, such as their cellular density and lack of blood vessels, contribute to their protective functions and their ability to form selective barriers. Other types of tissue mentioned would have distinct roles; for instance, nervous tissue is involved in transmitting nerve impulses, connective tissue supports and binds various structures in the body, while muscle tissue facilitates contraction and movement.