Test 49 (Pathology)

1. The following are true about atherosclerosis:

a. it occurs in the retinal artery

b. foamy macrophages are seen in type I plaque

c. thinning of the intima is a feature

d. proliferation of smooth muscle cells in the intima is typical

e. raised HDL is associated with atherosclerosis

Answer
a.F   b.F   c.F   d.T   e.F
Atherosclerosis typically affects the large to medium sized muscular artery. The retinal artery is an arteriole.
Plaque in the intima is a feature of atherosclerosis. In type I plaque, the surface of the plaque is smooth whereas in type II, it is cracked. Type II plaque is characterized by the presence of foamy macrophages filled with fat cells and inflammation.
The intima is thickened with proliferation of the muscle cells
Hypercholesterolaemia with raised LDL and low HDL is a known aetiology 

2. The following conditions may cause central retinal vein occlusion in a 
    young patient:

a. protein C deficiency

b. excess protein S

c. antithrombin III deficiency

d. atrial fibrillation

e. factor V Leiden mutation

Answer
a.T   b.F   c.T   d.F   e.T
Protein S deficiency rather than excess increases the risk of thrombosis.
Atrial fibrillation can cause retinal artery occlusion but not retinal vein occlusion.

3. The following are true about cerebral infarction:

a. the area of infarct tends to be wedge-shaped

b. it can result from thrombosis of the external carotid artery 
    disease

c. coagulative necrosis occurs in the brain tissue

d. cortical blindness can result from infarction of the anterior 
    cerebral artery

e. the necrotic tissue is eventually replaced by Schwann cells

Answer
a. T   b.F   c.F   d.F   e.F
Thrombosis of internal carotid artery rather than the external carotid artery can give rise to cerebral infarction.
Liquefactive necrosis occurs and the necrotic tissues are replaced by astrocytes.
Cortical blindness results from thrombosis of the middle or posterior cerebral artery.

4. The following conditions can give rise to metastatic calcification:

a. phthsical eye

b. sarcoidosis

c. renal failure

d. pulmonary tuberculosis

e. multiple myeloma

Answer
a.F   b.T   c.T   d.F   e.T
Metastatic calcification refers to calcium deposition in the presence of hypercalcaemia. This is different from dystrophic calcification in which calcification occurs in the presence of normal calcification.

5. In the presence of inflammation, the following are raised:

a. platelets

b. ferritin

c. caeruloplasmin

d. fibrinogen

e. complement proteins

Answer
a.T   b.T   c.T   d.T   e.T
In acute inflammation, the number of platelets is raised. As are the concentration of serum proteins including C-reactive proteins, transport proteins (ferritin and caeruloplasmin), complement proteins and proteins involved in coagulation.