How does the diameter of a blood vessel affect blood low rate and blood flow volume?

Question

How does the diameter of a blood vessel affect blood low rate and blood flow volume? How does increasing the viscosity of blood affect blood flow rate and volume?

Answer 1

Hi Joe,

 

Have you been taught Pouseille’s equation? According to this equation, blood flow is directly and very strongly related to 
blood vessel radius and is inversely proportional to viscosity. 

 

Blood flow = pi*ΔP*r⁴ / 8ηλ  

In this equation, r represents the radius of the vessel and η represents viscosity.

Answer 2

Joe, think of a blood vessel like a hose. What happens if you change the diameter of the hose or the thickness of what comes through the hose??