In cystic fibrosis, thick mucus can block the pancreatic ducts, preventing enzymes from reaching the duodenum. Which statement best explains this effect?

• A. The pancreas stops producing enzymes.
• B. The stomach neutralizes enzymes.
• C. The intestinal mucosa degrades enzymes.
• D. Thick mucus blocks the ducts, preventing enzymes from reaching the duodenum.

Answer: (D)

In cystic fibrosis, the digestive problem stems from blocked pancreatic ducts. Thick, sticky mucus plugs these ducts, so the enzymes produced by the pancreas can’t reach the duodenum where digestion occurs. The pancreas keeps making enzymes like lipase, proteases, and amylase, but they can’t get into the small intestine due to ductal obstruction, leading to poor digestion and fat malabsorption. This is why the statement that best explains the effect is that thick mucus blocks the ducts, preventing enzymes from reaching the duodenum. The other options aren’t correct because the pancreas isn’t stopping production, the stomach doesn’t neutralize these enzymes in a way that explains the problem, and the intestinal mucosa doesn’t degrade the enzymes.