Intrinsic asthma (old paper)

Correct Answer: C

Rationale: Intrinsic asthma is triggered by viral infections (C), a non-allergic mechanism. Choice A is false; extrinsic asthma is Type I hypersensitivity. Choice B is incorrect; extrinsic (atopic) is most common. Choice D is wrong; IgE levels are normal. Choice E (negative skin tests) is true but not listed. Page 726 notes C's viral trigger respiratory infections (e.g., RSV) provoke hyperresponsiveness without IgE, contrasting with A's allergic basis or B's prevalence.

Correct Answer: C

Rationale: Bacterial pneumonia is the most common cause of death in influenza epidemics (C), via superinfection. Choice A is false; respiratory infections outnumber UTIs in both sexes. Choice B is true; pneumonia is parenchymal infection. Choice D is incorrect; gram-negative rods (e.g., Klebsiella) dominate nosocomial cases, not Strep pneumoniae. Choice E (respiratory portal) is true. Page 747 confirms C's epidemiology influenza weakens defenses, leading to fatal bacterial overlay, unlike A's prevalence or D's pathogen.

Correct Answer: B

Rationale: Antigenic shift involves recombination of RNA segments with animal viruses (B), replacing haemagglutinin/neuramidase. Choice A is false; shift is major, drift is mutation. Choice C is incorrect; type B drifts (not shifts). Choice D is wrong; type A affects birds (e.g., H5N1). Choice E (ssRNA) is true. Page 752 defines B's shift pandemic-causing reassortment contrasts with drift's gradual change, distinguishing it over A's reversal or D's bird error.

Correct Answer: C

Rationale: The nasopharynx, part of the upper throat behind the nasal cavity, connects directly to several structures. The middle ear links via the Eustachian tube, regulating pressure and draining mucus. The oropharynx lies below, sharing a continuous passage for air and food. The nasal cavity opens into it anteriorly, forming the primary airway. However, the lacrimal glands, located near the eyes, connect to the nasal cavity via the nasolacrimal duct, not the nasopharynx directly tears drain into the nose, bypassing the nasopharynx. This indirect link makes lacrimal glands the exception. Understanding these anatomical relationships is key in respiratory health, as infections can spread via these connections, but the lacrimal glands' drainage path distinguishes them, aligning with their role in tear production rather than respiratory function.

Correct Answer: A

Rationale: Smallpox, caused by variola virus, is the only viral disease eradicated globally, declared so by WHO in 1980 after a vaccination campaign eliminated natural cases. Measles and German measles (rubella) persist measles sees outbreaks where vaccination lags, and rubella, though controlled, isn't eradicated. Influenza evolves yearly, evading elimination due to antigenic drift. Smallpox's success stemmed from its stable virus, effective vaccine, and no animal reservoir, unlike influenza's mutations or measles' human spread. This milestone showcases public health triumph, contrasting with ongoing battles against other respiratory viruses, underlining eradication's rarity and the need for sustained vaccination efforts.