What type of junction prevents leakage between adjacent epithelial cells?

Tight junctions are specialized connections between adjacent epithelial cells that play a crucial role in maintaining the integrity of the epithelial barrier. They are formed by a network of protein interactions that seal the gaps between the cells, preventing the passage of substances through the intercellular space. This structural arrangement ensures that materials must traverse the cells themselves rather than move between them, thereby regulating the flow of ions, water, and solutes.

The significance of tight junctions lies in their ability to create a selective barrier that differentiates bodily compartments, facilitating the proper function of epithelial tissues. For instance, in the intestinal epithelium, tight junctions help control nutrient absorption while keeping out potentially harmful pathogens and toxins. Thus, tight junctions are essential for maintaining homeostasis and protecting the underlying tissues from various external substances.