In the disease mononucleosis ("mono"), the spleen enlarges because of increased macrophage activity. Common symptoms of this disease include pale complexion, premature muscle fatigue, weakness, and a lack of energy, sometimes to the point of not being able to get out of bed. What might cause these symptoms?

Question

What will be an ideal response?

Answer 1

A major function of the spleen is to destroy old, defective, and worn-out red blood cells. As the spleen increases in size in cases of mononucleosis, so does its capacity to eliminate red blood cells, and this results in anemia. The decreased number of circulating red blood cells decreases the blood's ability to deliver oxygen to the tissues, and thus their metabolism is slowed down. This would account for the symptoms of muscle fatigue, weakness, and lack of energy. Because there are fewer red blood cells than normal, the blood circulating through the skin is not as red, and so the person has a pale or white skin coloration.