481. Metaplasia
A. is an increase in the number and size of cells in a tissue.
B. is the process that occurs in Barretts oesophagitis.
C. is typically an irreversible process.
D. preserves mucus secretion in the respiratory tract.
E. can be caused by vitamin B 12 deficiency.

482. The first vascular response to injury is
A. slowing of the circulation.
B. arteriolar vasoconstriction.
C. capillary engorgement.
D. recruitment of vascular beds.
E. venular dilation.

483. Leukocytes move into the tissues from the vasculature
A. by the actions of actin and myosin.
B. in response to the Fc fragment of IgG.
C. in response to C3b.
D. largely in the arterioles.
E. predominantly as monocytes in the first day post injury.

484. Regarding chemical mediators of inflammation
A. histamine is derived from plasma.
B. serotonin is preformed in mast cells.
C. nitric oxide is preformed in leukocytes.
D. the kinin system is activated in platelets.
E. C3b is within macrophages.

485. Regarding chronic inflammation, all of the following are true EXCEPT
A. it can be caused by persistent infections.
B. it can be caused by prolonged exposure to toxic agents.
C. it involves mononuclear inflammatory cells.
D. it may contribute to the formation of atherosclerosis.
E. it primarily involves tissue destruction.

486. Macrophages are derived from
A. monocytes.
B. T lymphocytes.
C. B lymphocytes.
D. eosinophils.
E. plasma cells.

487. White infarcts occur in the
A. small intestine.
B. kidney.
C. lung.
D. sigmoid colon.
E. oesophagus.

488.With regard to aortic dissection, which is false
A.It tends to occur in 40-60yo men
B.Approximately 90% of non-traumatic cases occur in patients with antecedent hypertension
C.It is usually associated with marked dilation of the aorta
D.It is unusualin the presence of substantial atherosclerosis
E.it is usually caused by an intimal tear within 10cm of the aortic valve

489. Regarding oedema
A. hypoproteinaemia is the most common cause of systemic oedema.
B. hepatic cirrhosis is the most common cause of hypoproteinaemia.
C. facial oedema is a prominent feature of anasarca.
D. hereditary angioneurotic oedema involves skin only.
E. infection does not cause pulmonary oedema.

490. The process of blood coagulation involves
A. prothrombin activator converting fibrinogen to fibrin.
B. the removal of pep tides from each fibrinogen molecule.
C. the action of plasmin on fibrin.
D. alpha 2 macroglobulin.
E. the action of antithrombin III to promote clotting.