511. With regard to acute myocardial infarction
A. gross necrotic changes are visible within 2-3 hours.
B. irreversible cell injury occurs in less than 10 minutes.
C. fibrotic scarring is completed in 2 weeks.
D. death occurs in 20% of cases within 2 hours.
E. it is most commonly caused by occlusion of the left circumflex coronary artery.
512. Endocarditis in IV drug users typically
A. involves the mitral valve.
B. is caused by candida albicans.
C. does not cause fever.
D. has a better prognosis than other causes of endocarditis.
E. is caused by staphylococcus aureus.
513. All of the following are major risk factors for atherosclerosis EXCEPT
514. Regarding pericarditis
A. fibrinous pericarditis is due to mycobacterium tuberculosis infection until proven otherwise.
B. serous pericarditis may be due to uraemia.
C. haemorrhagic pericarditis is most commonly due to Klebsiella infection.
D. primary pericarditis is usually bacterial in origin.
E. constrictive pericarditis only rarely follows suppurative pericarditis.
515. Regarding bronchogenic carcinoma
A. it most often arises around the hilum of the lung.
B. distant spread occurs solely by lymphatic spread.
C. metastasis is most common to the liver.
D. small cell carcinoma is the most common type.
E. surgical resection is often effective for small cell carcinoma.
516. In emphysema
A. a deficiency of alpha I-antitrypsin is protective.
B. elastase activity is unaffected by oxygen free radicals.
C. smokers have an increased number of macrophages in bronchi.
D. the protease – antiprotease mechanism is the most plausible explanation for disease.
E. centriacinar destruction leads to obstructive overinflation.
517.In chronic bronchitis
A. the hallmark is hypersecretion of mucous in the large airways.
B. there is a marked increase in goblet cells in main bronchi.
C. infection is a primary cause.
D. cigarette smoke stimulates alveolar leucocytes.
E. dysplasia of epithelium leads to emphysema.
518. In bronchial asthma
A. extrinsic asthma is initiated by diverse non-immune mechanisms.
B. sub-epithelial vagal receptors in respiratory mucosa are insensitive to irritants.
C. IgG immunoglobulins playa major role.
D. primary mediators include eosinophilic and neutrophilic chemotactic factors.
E. bronchial wall smooth muscle is atrophic.
519. In bacterial pneumonia
A. patchy consolidation of the lung is the dominant characteristic of bronchopneumonia.
B. the nasopharynx is inconsequential in defending the lungs against infection.
C. alveolar clearance of bacteria is achieved by lymphocytes.
D. Klebsiella pneumoniae is a common virulent agent.
E. a lobar distribution is a function of anatomical variations.
520. In pulmonary tuberculosis
A. the Ghon complex is a parenchymal peri-hilar lesion.
B. bacilli establish themselves in sites with low oxygen tension.
C. liquefactive necrosis precedes granuloma formation.
D. primary tuberculosis causes more damage to lungs than does secondary tuberculosis.
E. Langhans giant cells occur in coalescent granulomas.