MICROANATOMY

Detailed explanation-1: -Tight junctions bind cells together, prevent molecules from passing in between the cells, and also help to maintain the polarity of cells. They are only found in vertebrates, animals with a backbone and skeleton; invertebrates have septate junctions instead.

Detailed explanation-2: -Tight junctions prevent the passage of molecules and ions through the space between plasma membranes of adjacent cells, so materials must actually enter the cells (by diffusion or active transport) in order to pass through the tissue.

Detailed explanation-3: -Tight junctions (also called zonula occludens or occluding junctions) are a type of cell junction characterized by forming an adhesion complex between two neighboring cells serving as a tight seal between the cells. The tight junctions are essentially a protein complex between two cells.