cardiovascular dynamics

Is this a PhysioEx question? If so, post the question exactly how it is stated. Otherwise, reply back, I think I know what you're looking for.

Yes this is a Physioex 8.0 exercise 5 cardiovascular dynamics

The complete question is
When a blood vessel bifurcates (splits) into two smaller vessels, the radii of the two smaller vessels add up to a larger cumulative radius than the radius of the original vessel. However, blood flow is slower in the two vessels than in the original. Why?

Also from the same exercise are two other questions I am really stuck on if would appreciate help with are

What kind of change in the cardiovascular system would result in a pressure change?

Why would such a change cause problems?

Okay, do you know which activity?

The first question (when a blood vessel bifurcates) is from Activity 2 (The effect of vessel radius on blood flow)
The other two questions are from Activity 1 (The effect of pressure on blood flow)

Fluid flow increases as the radius of the flow tube is increased.

Because fluid flow is proportional to the fourth power of the radius, increases/decreases in tube radius cause increases/decreases in fluid flow. The relationship between fluid flow and flow tube radius is exponential. We alter blood flow in the human body by increasing or decreasing the diameter of blood vessels by the contraction or relaxation of smooth muscle tissue in vessel walls. After a heavy meal when we are relatively inactive, we might expect blood vessels in the skeletal muscles to be somewhat constricted while blood vessels in the digestive organs are probably dilated.

Hope this helps.

Thank you very much, it does help!