What is the primary function of epithelial tissue?

The primary function of epithelial tissue is indeed to form a barrier by connecting adjoining cell membranes. This type of tissue plays a crucial role in protecting the underlying structures of the body from physical damage, pathogens, and dehydration. Epithelial cells are tightly packed together, creating a continuous layer that can cover surfaces and line cavities as well as organs.

These cells not only provide protection but also serve other functions such as absorption, secretion, and sensation. The arrangement of cell membranes in epithelial tissue enables selective permeability, allowing certain substances to pass while blocking others. This characteristic makes epithelial tissue essential for maintaining homeostasis and regulating the internal environment of the body.

As for the other choices, they refer to functions associated with other types of tissues. For instance, transmitting electrical signals is primarily the role of nervous tissue, connecting body parts is the main function of connective tissue, and facilitating movement is characteristic of muscle tissue. Understanding the specific functions of different tissue types helps clarify why forming a barrier is the defining role of epithelial tissue.