681. After occlusion of a coronary artery
A. the ischaemia is most pronounced in the epicardial region
B. loss of contractility only occurs when ultra structural changes in the myocyte are present
C. reperfusion of the ischaemic area can result in new cellular damage, due to the generation of oxygen free radicals
D. Q waves on the ECG are diagnostic of transmural infarction
E. none of the above are true

682. With regard to aortic dissection, which is incorrect
A. it tends to occur in 40-60 year old men
B. approximately 90% of non-traumatic cases occur in patients with antecedent hypertension
C. it is usually associated with marked dilatation of the aorta
D. it is unusual in the presence of substantial atherosclerosis
E. it is usually caused by an intimal tear within 10cm of the aortic valve

683. The most common site of origin of emboli causing cerebrovascular disease is
A. common carotid artery
B. internal carotid artery
C. the heart
D. either end of basilar artery
E. intracranial vessels

684. Which of the following is malignant
A. Squamous cell papilloma
B. Hydatidifonn mole
C. Chondroma
D. Mature teratoma
E. Bronchial carcinoid

685. Anaplasia is not characterised by
A. pleomorphism
B. Abundant nuclear DNA
C. A nuclear-cytoplasmic ratio of 1:6
D. Coarsely clumped chromatin
E. Lack of differentiation

686. All of the following are precancerous except
A. Chronic gastritis of pernicious anaemia
B. Solar keratosis
C. Crohn’s disease
D. Leukoplakia
E. Chronic ulcerative colitis

687. Prothrombogenic factors include all of the following except
A. Platelet activating factor
B. Von Willebrand factor
C. Nitric oxide
D. Tissue factor
E. tP A inhibitor

688. In acute inflammation, all of the following are true except
A. there is contraction of endothelial cells
B. there is a mononuclear infiltrate
C. there is induction of adhesion molecules on endothelium
D. there is production of arachidonic acid metabolites
E. cytokines induce a systemic acute phase response

689. Cellular events in acute inflammation include all of the following except
A. redistribution of prefonned adhesion molecules to the cell surface of leukocytes
B. adhesion and transmigration of leukocytes to endothelium
C. leukocyte activation
D. margination of macrophages to vessel walls
E. extracellular release of lysosomal enzymes and products of arachidonic acid metabolism

690. The factor conferring the most risk in thromboembolic disease is
A. smoking
B. atrial fibrillation
C. oral contraceptives
D. prolonged bed rest
E. late pregnancy I post delivery