Advanced Patient Assessment Practice Exam

What is the typical lifespan of a red blood cell?

1. 120 days

2. 30 days

3. 60 days

4. None of the above

The correct answer is: 120 days

The typical lifespan of a red blood cell (RBC) is approximately 120 days. This duration is important because it reflects the natural cycle of erythropoiesis, the process of producing red blood cells in the bone marrow. Once these cells are released into the bloodstream, they carry oxygen to tissues and organs, and after several weeks, they undergo physical changes that trigger their removal from circulation, primarily by the spleen and liver. Understanding the lifespan of red blood cells assists in diagnosing various hematological conditions. For example, in conditions such as anemia or hemolytic disorders, a significantly shortened lifespan of RBCs might contribute to a patient's symptoms and the lab findings observed. Recognition of this lifespan also informs healthcare professionals about the timing of blood tests and transfusions, as well as the body’s response to blood loss or increased demand for red blood cells. The other options indicate lifespans that are not accurate for red blood cells, reflecting a misunderstanding of hematological science or perhaps confusing RBCs with other types of cells within the body that might have shorter lifetimes. In clinical practice, this knowledge is key to understanding patient health and managing treatment effectively.