Which of the following are pathological features associated with HbS?
I.Thromboemboli
II.Ischemia
III.Polycythemia
IV.Tissue hypoxia

Question

Quizplus · Accepted Answer

Sickle cell hemoglobin (HbS) is much less soluble than HbA in the deoxygenated state. Thus HbS tends to crystallize in the red blood cell on deoxygenation, changing the red cell from biconcave to a curved, sickle shape. The sickle-shaped cell is fragile and subject to rupture. Its shape also causes it to tangle with other sickle cells, and they clump together to form thromboemboli (blood clots). These may block blood flow through small vessels, creating painful areas of ischemia or tissue hypoxia. The sickle cell's fragility and ease of rupture also predisposes the patient to develop anemia. Sickle cell anemia is an inherited blood disorder. The sickling phenomenon is not always present in people with sickle cell disease, but it may be precipitated by prolonged episodes of hypoxia.

Which of the Following Are Pathological Features Associated with HbS