Final Answer:
The effect of polycythemia vera that leads to an increased tendency to develop blood clots is Increased blood viscosity. Thus option 2 is correct.
Step-by-step explanation:
Polycythemia vera is a condition characterized by an overproduction of red blood cells (RBCs), which leads to increased blood viscosity. Viscosity refers to the thickness or stickiness of a fluid. In this case, with an elevated number of RBCs, the blood becomes thicker, impeding its flow through the blood vessels and increasing the risk of blood clots.
Blood viscosity is directly influenced by the concentration of RBCs. The hematocrit level, which measures the proportion of RBCs in the blood, is elevated in polycythemia vera. This elevation in hematocrit directly correlates with increased blood viscosity. According to the law of Poiseuille, an increase in viscosity significantly impedes blood flow through vessels, leading to a higher chance of clot formation.
Increased viscosity from elevated RBC count can result in sluggish blood flow, particularly in smaller blood vessels. This slow movement predisposes the blood to clot formation, as platelets and other clotting factors have more time to accumulate and initiate clotting. This heightened clotting risk is a key concern in polycythemia vera, necessitating monitoring and interventions to reduce clotting tendencies.
In managing polycythemia vera, treatment often involves therapeutic phlebotomy to reduce blood viscosity by decreasing RBC count, thereby lessening the risk of clot formation. Educating patients about the importance of adhering to treatment plans to control blood viscosity is crucial in preventing complications related to clot formation. Thus option 2 is correct.