Certified Nurses Operating Room (CNOR) Practice Exam

Which organ is primarily responsible for phagocytosis of red blood cells?

1. Liver

2. Spleen

3. Lungs

4. Kidneys

The correct answer is: Spleen

The spleen plays a crucial role in the phagocytosis of red blood cells. This organ is part of the lymphatic system and is located in the upper left abdomen. It acts like a filter for the blood, removing old or damaged red blood cells through a process called hemolysis. The spleen contains specialized cells, such as macrophages, that effectively engulf and break down these cells, recycling important components like iron for the body’s use. While the liver also processes blood and plays a role in the destruction of old red blood cells, its primary function is more about bile production and detoxification rather than direct phagocytosis. The lungs are primarily involved in gas exchange and are not associated with the phagocytosis of blood cells. The kidneys are primarily responsible for filtering blood to produce urine and also do not engage directly in the phagocytosis of red blood cells. Therefore, the spleen is the primary organ responsible for this function, making it the correct answer.