Final answer:
The correct statement is that high resistance results in low blood flow. This inverse relationship is governed by factors such as vessel length, blood viscosity, and vessel diameter, all affecting the rate of flow through the cardiovascular system.
Step-by-step explanation:
The relationship between resistance and blood flow is an inverse one, where high resistance leads to low flow, and low resistance leads to high flow. This concept is crucial in understanding cardiovascular physiology. A longer vessel has more resistance, thus decreasing flow. Similarly, an increase in blood viscosity leads to higher resistance and therefore lower flow as well. Vessel diameter plays a critical role too; slight changes in diameter can drastically impact flow due to the radius being to the fourth power in the formula for resistance.
Turbulence increases resistance, which is significant in situations with constrictions, such as in the case of arterial plaque, resulting in reduced pressure and flow downstream. Therefore, among the options provided, the statement that 'When resistance is high, flow is low' is the one that best reflects the relationship between resistance and blood flow.