Question

If an individual had a bone marrow cancer and there was a large increase of red blood cell production (polycythemia) what would happen to blood flow?

a) it would initially have a slight increase and then later rise significantly

b)it would cause a decrease

c) it would cause a large increase

d) it wouldn’t have any effect

Answer 1

Bone marrow cause increased proliferation of bone marrow hematopoietic stem cells in humans. Multiple myeloma, leukemia and lymphomas are different types of bone marrow cancer. In this patient, there is increased production of red blood cells, which is kwown as polycythemia. Increased numbe rof RBCs in blood leads to increase hematocrit, and thus, also to increased levels of Hemoglobin.

The increased number of red blood cells will cause increased thickening of the blood. This will reduce the blood flow as the blood becomes highly viscous. It is known that when the hematocrit increases from 40% to 60%, there is a 100% increase in blood viscosity. Increased viscosity is known to increase total peripheral resistance (TPR) to the flow of blood. As TPR increases, the blood flow should decrease. Thus, there is an effect of increased red blood cells on blood flow. Blood flow will decrease and not increase as there is increased resistance to blood flow in blood vessels due to higher number of red blood cells.

Right choice: b) it would cause a decrease.