Final answer:
Epithelial cells are held together by tight junctions, anchoring junctions, and gap junctions. Tight junctions create a watertight seal between cells, anchoring junctions provide strong and flexible connections, and gap junctions form intercellular passageways between cells.
Step-by-step explanation:
Epithelial cells are held together by tight junctions, anchoring junctions, and gap junctions. Tight junctions create a watertight seal between cells, blocking the movement of substances through the extracellular space. Anchoring junctions provide strong and flexible connections and include desmosomes, hemidesmosomes, and adherens junctions. These junctions use structural proteins like cadherins and integrins to hold cells together. Gap junctions form intercellular passageways between cells, allowing the free exchange of molecules.