In chronic bronchitis (old paper)

Correct Answer: A

Rationale: The hallmark of chronic bronchitis is mucus hypersecretion in large airways (A), from gland hypertrophy'. Choice B is false; goblet cells increase markedly in small airways, not main bronchi. Choice C is incorrect; infection maintains, not initiates, disease (smoking is primary). Choice D is true; smoke activates alveolar macrophages. Choice E (dysplasia to emphysema) oversimplifies. Page 722 defines A as the core feature excess mucus from hypertrophied glands and goblet cells clogs large airways, distinguishing it over B's location or C's causality.

Correct Answer: C

Rationale: Hypersensitivity pneumonitis is partly caused by Type III hypersensitivity (C), with immune complexes and Type IV granulomas. Choice A is false; it's distinct from asthma (alveolar focus). Choice B is incorrect; it's from organic dusts (e.g., fungi), not non-organic. Choice D is wrong; it's allergic alveolitis, not bronchiolitis. Choice E (non-caseating granulomas) is true. Page 739 details C's mechanism antigen-antibody complexes trigger inflammation (e.g., farmer's lung), distinguishing it over A's link or B's dust type.

Correct Answer: A

Rationale: Staph aureus pneumonia is common with endocarditis in IV drug users (A), via hematogenous spread. Choice B is false; it causes complications (e.g., empyema). Choice C is incorrect; Klebsiella, not S aureus, targets malnourished/alcoholics. Choice D is wrong; it follows viral infections (e.g., influenza), not mumps. Choice E (nosocomial) is true. Page 748 links A's association S aureus's virulence in IVDU leads to septic emboli, distinguishing it over B's complication denial or C's group error.

Correct Answer: A

Rationale: Pulmonary non-Hodgkin lymphoma must be excluded in HIV pneumonia (A), due to malignancy risk. Choice B is false; common pathogens (e.g., S pneumoniae) also dominate. Choice C is incorrect; M avium occurs late (CD4 <50). Choice D is wrong; TB strikes early. Choice E (none true) is invalid. Page 757 notes A's necessity lymphoma mimics infection radiologically, distinguishing it over B's exclusion or C's timing error.

Correct Answer: A

Rationale: Adhesins are proteins or structures on microbial surfaces that enable attachment to host respiratory tissues, a critical step in infection. They bind to specific receptors on epithelial cells, like those in the lungs or nasal passages, allowing pathogens to colonize and evade clearance. Lipopolysaccharide, a bacterial endotoxin, triggers inflammation but doesn't aid attachment. Hyaluronidase degrades host tissues for invasion, not initial adhesion. Capsules resist phagocytosis but primarily protect, not attach. Adhesins' specificity e.g., in Streptococcus pneumoniae or influenza virus makes them vital for establishing respiratory infections, initiating pathogenesis. This attachment precedes toxin release or tissue damage, underlining its importance in microbial strategies, a key focus in understanding respiratory disease mechanisms.