AEMCA Practice Exam

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Prepare for the AEMCA Exam with flashcards and multiple-choice questions, complete with hints and explanations. Get exam-ready today!

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What is the average lifespan of a red blood cell (RBC)?

60 days
90 days
120 days
150 days

The correct answer is: 120 days

The average lifespan of a red blood cell (RBC) is approximately 120 days. This lifespan is significant because it reflects the time a red blood cell can efficiently perform its essential functions, which include transporting oxygen from the lungs to the tissues and returning carbon dioxide from the tissues back to the lungs for exhalation. RBCs are continuously produced in the bone marrow and have a finite life due to wear and tear; as they circulate through the bloodstream, they gradually lose their functionality. After about 120 days, they are typically removed from circulation by the spleen and liver, where they are broken down and recycled. This cycle of life ensures that the blood remains efficient in its gaseous exchange functions, as older cells may become less effective. Lifespans that are shorter, such as 60 days, 90 days, or even 150 days, do not accurately reflect the established biological processes of red blood cell turnover and the maintenance of optimal blood function. This knowledge is crucial for understanding hematology and various medical conditions related to blood health.