Characteristics of radius of blood vessel **Which properties do determine the radius of blood vessel?** I have these thoughts * distension, * elasticity, * contractility and * cross-sectional area of the walls. **Is there any other properties?**

The radius of a blood vessel is entirely defined by only two parameters:

1.blood pressure

2.compliance of the vessel walls

Of course, active contraction can decrease the vessel radius. Physically, this is a decrease in compliance, so the above relation always remains true.