What is the typical lifespan of adult red blood cells?

The typical lifespan of adult red blood cells is approximately 120 days. This lifespan is critical for understanding various physiological processes in the body, particularly in relation to oxygen transport and overall hematologic health. Red blood cells, or erythrocytes, originate from the bone marrow and are released into circulation. They are responsible for carrying oxygen from the lungs to tissues and returning carbon dioxide from tissues to the lungs for exhalation.

During their lifespan, red blood cells undergo various changes, including the gradual loss of their cell membrane flexibility and the ability to pass through capillaries. After about 120 days, they are typically removed from circulation by the spleen and liver in a process called senescence. Knowledge of this lifespan is essential for healthcare providers when evaluating conditions such as anemia, where the production or lifespan of red blood cells may be compromised.

The incorrect options reflect either an underestimation or an overestimation of the lifespan of red blood cells. Understanding the physiological lifecycle of red blood cells helps inform clinical decision-making and interpretation of lab results in neonatal and pediatric care.