Why does thickened mucus in the alveoli of cystic fibrosis patients impair gas exchange more than reduced lung elasticity?

💡 Explanation

Thickened mucus directly impedes the diffusion of oxygen and carbon dioxide across the alveolar membrane because it increases the diffusion distance and reduces the concentration gradient. Therefore, gas exchange is severely compromised. Reduced elasticity affects ventilation, rather than the efficiency of diffusion at the alveolar surface.

• If osteocytes within bone experience reduced mechanical loading due to prolonged bed rest, which consequence follows concerning bone density?
• If a woman experiences consistently short luteal phases due to inadequate progesterone secretion after ovulation, what consequence becomes most likely, assuming normal follicle development and fertilization?
• If a drug with high hepatic extraction is administered orally but shows unexpectedly high bioavailability, which mechanism explains this observation?
• Why does the absorption rate of orally administered cyclosporine (an immunosuppressant) vary significantly between patients with similar dosages, especially post-digestive processing?
• What distinguishes angiotensin II's vasoconstrictive effect in chronic hypertension from its role in acute blood pressure regulation?
• Why does neuronal function decline during neurodegenerative diseases featuring protein aggregates like amyloid plaques or Lewy bodies?