Ability to maintain vascular tone

2021-05-31 04:55 PM

The capacity to change the tone of the systemic veins is about 24 times that of the corresponding arteries because of its 8 times the elasticity and about 3 times the volume.

In hemodynamic studies, it is often more important to know the total amount of blood that is stored in each unit of circulation per mmHg increase than to measure the elasticity of individual vessels. blood. This value is called the tonic or capacitance of the blood vessel relative to the lumen, which is:

Capacity to maintain tone = (increase in volume)/(increase in pressure)

The ability to maintain tone and the ability to stretch is not the same. A highly elastic vessel containing a small volume may also be far less adaptive than a vessel with a low elasticity containing a large volume of blood because its ability to maintain tone is equal to its ability to contract. elasticity times volume.

The ability to change the tone of the systemic veins is about 24 times that of the corresponding arteries because of its 8 times the elasticity and about 3 times the volume (8 x 3=24).