What is the predominant function of epithelial tissue in the body?

Epithelial tissue primarily serves the function of covering and lining surfaces throughout the body. This type of tissue acts as a protective barrier for the underlying structures, including the skin's outer layer, the lining of organs, and the surfaces within cavities. Epithelial cells are closely packed together, which helps to create a continuous sheet that protects against mechanical injury, pathogens, and fluid loss.

Additionally, epithelial tissue forms the selective barrier for absorption, filtration, and secretion processes. For example, it lines the intestines where nutrients are absorbed and also covers the respiratory tract where it plays a role in mucus secretion and trapping pathogens.

The other choices focus on different tissue types or functions that are not primarily the role of epithelial tissue. Support and protection pertain more to connective tissues, while facilitating movement is characteristic of muscular tissues. Transmitting signals is typical of nervous tissue. Therefore, the unique role of epithelial tissue in covering and lining surfaces makes it essential for maintaining the integrity of body systems.