Which of the following substances is NOT synthesised by the lung?

Correct Answer: B

Rationale: serotonin (5-HT) is not synthesized by the lung it's produced by enterochromaffin cells and neurons, then removed by pulmonary endothelium (monoamine oxidase). Choice A (prostaglandins) is synthesized (e.g., PGIâ‚‚ by endothelium). Choice C (DPPC) is made by Type II pneumocytes (surfactant). Choice D (histamine) is produced by mast cells. Choice E (kallikrein) is lung-derived. The lung metabolizes serotonin but lacks tryptophan hydroxylase for synthesis, distinguishing B as the non-synthesized substance.

Correct Answer: B

Rationale: After recovering from influenza, Emily Yi might use cough suppressants for lingering symptoms, but the nurse warns against overuse because they reduce coughing's effectiveness during the day. Coughing clears mucus from the airways, a vital recovery mechanism post-flu, especially to prevent bacterial complications like pneumonia. Suppressing this reflex too much, particularly when active, traps secretions, increasing infection risk a concern for a healthy 27-year-old aiming to avoid setbacks. Weight gain from syrup calories is minor and unrelated to respiratory health. Sleepiness or insomnia could occur with some formulations (e.g., dextromethorphan), but this isn't the primary issue airway clearance is. Addiction to cough suppressants requires excessive, prolonged use, unlikely here. The nurse's focus is on preserving the body's natural defense post-viral illness, ensuring Emily's lungs stay clear, aligning with post-flu care principles to prevent secondary issues.

Correct Answer: C

Rationale: The most effective health promotion for seniors to prevent influenza and pneumonia is getting an annual flu vaccine. It primes immunity against prevalent strains, reducing infection risk by up to 60% when matched, and lowers pneumonia odds a common flu complication in older adults with waning immunity. Exercise boosts general health but doesn't target flu-specific prevention. Hand washing curbs germ spread but lacks the proactive immunity of vaccination. Avoiding crowds reduces exposure yet isn't as reliable or comprehensive as the vaccine, especially for community-dwellers. The nurse emphasizes this annual shot, often high-dose for seniors, as the gold standard, per CDC, offering direct protection against flu's severe outcomes, critical for this high-risk group's respiratory health.

Correct Answer: A

Rationale: In ARDS, alveolar walls are lined with waxy hyaline membranes (A), resembling surfactant insufficiency in preterm infants'. Choice B is false; initial damage targets capillary endothelium, later affecting epithelium. Choice C is incorrect; the exudate leads to intra-alveolar fibrosis, not resolution. Choice D is wrong; chest X-rays are often normal initially, showing infiltrates later. Choice E (neutrophil-mediated) is true but not listed. Page 716 details hyaline membranes protein-rich debris from necrosis as a hallmark, driven by neutrophil mediators (e.g., ROS), distinguishing A as the consistent feature over B's epithelial focus or C's resolution.

Correct Answer: C

Rationale: Atopic asthma (C) is the most common type, driven by allergens'. Choice A is false; asthma has increased in the Western world over 30 years. Choice B is incorrect; intrinsic asthma is non-allergic (e.g., viral), while extrinsic is allergen-induced. Choice D is wrong; T_H2 cells (not T_H1) dominate, promoting IgE via IL-4/IL-13 (T_H1 inhibits). Choice E (bronchiolitis obliterans) is bronchitis-related. Page 723 confirms C's prevalence atopy's IgE-mediated hypersensitivity underlies most cases, unlike A's trend or D's cell error.