Final answer:
Approximately one-third of the platelet pool is stored in the spleen, equating to around 33%. Platelets have a 10-day lifespan and are essential for blood clotting. Hemopoiesis constantly replaces them in the bone marrow.
Step-by-step explanation:
About one-third of the platelet pool is stored in the spleen, which plays a significant role in the storage and release of platelets to maintain blood consistency and aid in clotting when necessary. Since a third represents approximately 33.33%, the correct answer to the question is 33%. This is critical for the body's hemostatic function to limit blood loss due to vessel injuries. Platelets have a brief lifespan in the circulation, lasting only about 10 days, after which they are typically phagocytized by macrophages, mainly in the spleen and liver. New platelets, therefore, must be continuously produced through a process called hemopoiesis, which occurs in bone marrow. Understanding the function and lifecycle of platelets provides insight into the complex system of blood regulation and the body's healing processes.