Answer to Question 1
ANS: D
Sickled cells undergo hemolysis in the spleen or become sequestered there, causing blood pooling and infarction of splenic vessels. The hemolysis of sickled cells does not occur mainly in the liver, the pancreas, or the kidneys.
Answer to Question 2
ANS: B
Vasoocclusive crisis is extremely painful and may last for days or even weeks, with an average duration of 4-6 days. Vasoocclusive crisis does not promote peripheral edema, petechiae, or an enlarged spleen.