Regarding pneumoconioses

Correct Answer: B

Rationale: The most dangerous inhaled particles are 1-5 μm (B), reaching alveoli to cause fibrosis. Choice A is false; cases decline in the West due to regulation. Choice C is incorrect; larger particles (>10 μm) are filtered, causing less injury than 1-5 μm. Choice D is wrong; silica activates macrophages, releasing fibrogenic mediators (e.g., TNF), not inhibits. Choice E (not all exposed develop disease) is true. Page 733 confirms B's size range optimal for deep penetration and inflammation, unlike A's trend or D's mechanism.

Correct Answer: B

Rationale: Lobar pneumonia involves red to grey hepatization (B), marking RBC disintegration in consolidation. Choice A is false; Streptococcus pneumoniae is the most common cause. Choice C is incorrect; productive cough is typical. Choice D is wrong; atypical pneumonia, not lobar, links to immunosuppression. Choice E (age-specific) is a marker, not cause. Page 750 details B's sequence congestion to resolution via hepatization reflects S pneumoniae's progression, unlike A's rarity or C's cough denial.

Correct Answer: A

Rationale: Bronchogenic carcinoma often arises near the hilum (A), especially squamous cell. Choice B is false; metastasis is hematogenous and lymphatic. Choice C is incorrect; adrenals (>50%) outrank liver (30-50%). Choice D is wrong; adenocarcinoma/SCC (25-40%) exceed small cell (20-25%). Choice E (small cell resection poor) is true. Page 759 confirms A's origin hilar proximity reflects bronchial irritation, unlike B's spread or D's type error.

Correct Answer: C

Rationale: Pertussis, or whooping cough, progresses through stages. The catarrhal stage mimics a cold with runny nose and mild cough. The paroxysmal stage follows, featuring severe, uncontrollable coughing fits ending in a high-pitched 'whoop' as air is inhaled forcefully through a narrowed airway Bordetella pertussis's toxin damages cilia, causing this. Convalescence is recovery, with diminishing cough. Prodromal isn't a recognized stage here catarrhal serves as the early phase. The whooping sound in the paroxysmal stage, peaking 2-6 weeks after onset, is diagnostic, reflecting airway obstruction and mucus buildup, critical for identifying this vaccine-preventable disease and initiating supportive care and antibiotics.

Correct Answer: C

Rationale: Histoplasmosis, from Histoplasma capsulatum, thrives in soil enriched by bird or bat droppings, peaking in the Mississippi River Valley, where humid conditions favor spore dispersal, causing lung infections via inhalation. The Pacific Northwest has fewer cases cooler, less bat-heavy. The desert southwest suits coccidioidomycosis, not histoplasmosis. The Colorado River Valley lacks the specific ecology for Histoplasma. The Mississippi region's 'histo belt' links to farming and river systems, driving endemicity cases mimic flu or progress to disseminated disease in the immunocompromised, requiring itraconazole, unlike other regions' fungal profiles, key for geographic disease mapping.