1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Arterial blood flow

  1. Jun 17, 2009 #1
    Dear all,

    I am trying to find a mathematical explanation for why a blood vessel's lumen, especially an artery's, expands when the heart forces blood through the vessel upon contraction of the myocardium. This expansion is clearly evident when taking a person's pulse.

    I have some ideas but I am quite confused considering all of the variables.

    Firstly, I took the idea of volumetric flow rate and worked from there:
    [tex]Q=A\cdot v[/tex]

    Q blood flow rate through the vessel (volume per unit time)
    A cross-sectional area of the vessel lumen
    v velocity of blood flow

    Now I seem to remember that (area)(velocity) = constant, though this would imply that the the vessel would constrict as the velocity of the blood increases after a heart contraction!?

    I then took A, the cross-sectional area of the vessel lumen, and considered it in relation to blood pressure(from the pressure formula):
    [tex]A=\frac{F}{p}[/tex]

    F force exerted on the vessel wall by the blood


    ....AND there I got stuck. It has been annoying me all day and I would quite like to find an answer for it! I seem to be unable to link my medical knowlege with my physics knowlege at this point - perhaps I'm looking at the wrong variables.


    Many thanks,
    James
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted