Final answer:
The statement is false; mean arterial blood pressure increases with greater blood viscosity and volume, rather than decreases.
Step-by-step explanation:
The statement is false: The mean arterial blood pressure increases with increases in blood viscosity and blood volume.
In terms of blood volume, the relationship between blood volume, blood pressure, and blood flow is analogous to water flowing in a creek. Just as water rushes quickly and under great pressure after a heavy rain, as blood volume increases, both pressure and flow increase. Consequently, a decrease in blood volume would lead to a decreased blood pressure and flow, not the other way around.
Considering blood viscosity, it is understood that an increase in viscosity typically leads to an increase in resistance to flow, which can result in a higher blood pressure to maintain circulation, assuming that the heart can compensate for this increase in resistance.