During inflammation, why might a drug with paracellular transport pass through more easily?

• A. Cell membranes become more rigid
• B. Tight junctions loosen and become more permeable
• C. Active transport pumps increase
• D. Paracellular transport decreases

Answer: (B)

Inflammation weakens the barrier between neighboring cells by loosening tight junctions, which are the gates of the paracellular route. When these junctions become more permeable, the spaces between cells widen and the paracellular pathway allows more molecules to pass. A drug that relies on paracellular transport will therefore cross more easily because the barrier it must traverse is less restrictive.

Think of it as the "between cells" route becoming more open during inflammation, rather than the cell membranes themselves becoming more permeable or active transport processes stepping up. If membranes were stiffer, or if paracellular routes were actually reduced, the drug wouldn’t gain easier access. Increased active transport would affect transcellular movement, not the paracellular path.