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## Blood vessels

Human Anatomy, Physiology, and Medicine. Anything human!

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### Blood vessels

HI can someone help me with this homework question please
Last edited by arsenal12345 on Mon Oct 05, 2009 6:19 am, edited 1 time in total.
arsenal12345
Garter

Posts: 4
Joined: Wed Sep 30, 2009 7:31 am

Generally, when the area doubles, the pressure halves.
Area of a circle: pi*r^2

Happy calculating!

P.S. Dude, you got some big ass blood vessels. What are you studying, whales? ;)

biohazard
King Cobra

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Joined: Sun Apr 08, 2007 6:45 pm

Flow = velocity * cross sectional area, technically it's the dot product of the flow component normal to your c-sect area.
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
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mith
Inland Taipan

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Location: Nashville, TN

### Re: Blood vessels

I know flow = Pressure/resistance and Resistance = 1/radius^4

so for 4cm vessel , i got resistance of 3.9x10^-3 and for 1cm vessel i got resistance = 1

so does pressure have to increase by a factor of 256? i'm really not sure on this one
arsenal12345
Garter

Posts: 4
Joined: Wed Sep 30, 2009 7:31 am

your resistance formula might be wrong...
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

mith
Inland Taipan

Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN

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