Final answer:
The brown color in the spleen in sickle cell anemia is primarily due to the 4. accumulation of hemosiderin, a pigment that stores the iron from the excessive hemolysis of abnormally shaped red blood cells caused by unstable hemoglobin S.
Step-by-step explanation:
The main cause of the brown color in the spleen due to auto-splenectomy in sickle cell anemia is the accumulation of hemosiderin. Hemosiderin is a pigment that is derived from hemoglobin, the oxygen-carrying molecule in red blood cells (RBCs). In the condition of sickle cell anemia, there is excessive hemolysis, or breakdown, of RBCs due to the instability of hemoglobin S (HbS). The iron from this hemolysis is stored in the form of hemosiderin within the spleen. Over time, repeated splenic infarctions and the chronic breakdown of sickled RBCs in sickle cell anemia lead to the hemosiderin accumulation, giving the spleen a brownish color and rendering it fibrotic and shrunken.
The main cause of the brown color in the spleen in the context of sickle cell anemia is the accumulation of hemosiderin.
Hemosiderin is an iron-storage complex that forms when red blood cells break down. The shrunken, fibrotic spleen in sickle cell anemia accumulates hemosiderin, leading to the brownish color. This accumulation occurs due to the repeated splenic infarctions, which are the result of sickle-shaped cells getting lodged in narrow capillaries and blocking blood flow to the spleen.