Question
If radius of a vessel is doubled then the blood flow is increased by:
| A. |
32 times |
| B. | 16 times |
| C. |
256 times |
| D. |
8 times |
Show Answer
|
Correct Answer � B Explanation |
 |
Options B – 16 times:
The influence of lumen diameter on resistance is dramatic. This is because resistance is inversely proportional to the radius of the blood vessel ( One-half of the vessel’s diameter) raised to the fourth power. (R= 1/r4).
This means, that of an artery or arteriole constricts to one-half of it’s original radius, the resistance to flow will increase 16 times.