The school nurse is talking to fifth graders about the use of tissues when blowing one's nose. Which cause of a runny nose should the nurse include in the teaching session?

Correct Answer: A

Rationale: A runny nose during influenza occurs because cells lining the respiratory passages die due to viral infection, releasing fluid and triggering inflammation, which increases mucus production. This is a key immune response to trap and expel the virus, appropriate for fifth graders to understand as a body defense. Drinking water doesn't cause runny noses it hydrates, not floods, the nose. Insufficient coughing or sneezing might worsen congestion but isn't the root cause mucus forms regardless. Viruses don't ‘melt' into fluid; they're already microscopic and trigger fluid release via cell damage, not fever directly. The nurse teaches this cellular explanation to connect symptoms to infection, making it relatable and scientifically sound, encouraging tissue use to manage mucus and reduce germ spread among kids.

Correct Answer: A

Rationale: The nurse asks if the 6-month-old has trouble breathing to gauge acuity, as respiratory distress (e.g., rapid breathing, grunting) in infants signals severe flu complications like bronchiolitis, needing urgent care. Small airways and immature immunity make this critical too young for flu shots, they're at high risk. Fever matters, but alone doesn't define urgency. Nasal drainage is typical, not acute. Symptom onset aids context, not immediate severity. Prioritizing breathing aligns with pediatric triage, ensuring the parent seeks help if this red flag appears, protecting the infant from rapid deterioration common in flu-related respiratory crises.

Correct Answer: C

Rationale: The protease-antiprotease mechanism (C) is the most plausible explanation for emphysema'. Choice A is false; α₁-antitrypsin deficiency causes panacinar emphysema, not protects. Choice B is true; centriacinar destruction overinflates via obstruction. Choice D is incorrect; macrophages increase in alveolar spaces, not bronchi. Choice E (elastase up with radicals) is true but not listed. Page 721 links smoking's oxidative stress and neutrophil elastase to alveolar damage, with α₁-antitrypsin's protective role overwhelmed, making C's imbalance theory central, unlike A's reversal or D's location error.

Correct Answer: B

Rationale: Aspirin-induced asthma occurs in patients with allergic rhinitis and nasal polyps (B), part of the aspirin-exacerbated respiratory disease triad. Choice A is false; it's a contraindication (MIMS warns of bronchospasm). Choice C is incorrect; minute doses trigger it. Choice D is wrong; aspirin inhibits cyclooxygenase, shunting to leukotrienes (lipooxygenase), not inducing COX. Choice E (urticaria) is true but not listed. Page 726 explains B's association 10-20% of asthmatics with polyps/rhinitis react, with leukotrienes causing constriction, distinguishing it over A's safety or D's mechanism.

Correct Answer: C

Rationale: Sarcoidosis causes bilateral hilar lymphadenopathy (C) in 90% of cases. Choice A is false; its cause is unknown (possible immune dysregulation), not silica (pneumoconiosis). Choice B is incorrect; granulomas are non-caseating. Choice D is wrong; lung pathology is most common, followed by eye/skin lesions. Choice E (more in women) is true. Page 737 confirms C's radiographic hallmark hilar nodes distinguish it, unlike A's etiology or B's necrosis error.