Question

How does vascular friction decrease pressure?

Answer 1

I take it that by vascular friction- you meant vascular resistance.

• increase in vascular resistance increases blood pressure.
• vascular resistance is mainly dependent on the diameter of the blood vessel and viscosity of blood.
• if the blood vessel is narrow, the resistance offered to the blood flow is high, so the pressure is higher on the walls of blood vessel , and the flow of the blood will be slower through this vessel.

the concept actually comes from physics. just imagine you drinking milk shake through a narrow straw and a wider straw. in which case you can finish the drink faster?

straw here is blood vessel and milk shake is blood...