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Old 02-12-2012
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Vascular Pressure, Flow, and Resistance in Heart Failure

In congestive heart failure, how the following factors change?
--Venous pressure, Venous resistance, Capillary flow, Capillary pressure

A) Increased, Decreased, Decreased, Increased
B) Increased, No Change, Decreased, Increased
C) Increased, Increased, Decreased, Increased
D) Decreased, Increased, Increased, Increased
E) Increased, No change, Increased, Decreased
F) Decreased, decreased, no change, no change
G) No change, No change, Increased, decreased

Source: Kaplan/Physiology
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Old 02-12-2012
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Ans .......C.........
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Old 02-12-2012
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answer is C....
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Old 02-12-2012
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Default Ans

Ans : c....
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Old 02-12-2012
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Quote:
Originally Posted by drgokult View Post
Ans : c....
Why it's not B? Because of venous compliance, may be we don't have significant increase in venous resistance, although total vascular resistance is increased due to sympathetic tone in CHF.
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Old 02-12-2012
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can someone please explain it a little more
thank you
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Old 02-17-2012
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Not quite sure what "venous resistance" imply here. "Vascular resistance" would have been a much better term which basically implies the resistance offered by the arterioles to the blood being pumped - which obviously will be more in heart failure 'cause of the sympathetic surge and reduced arteriolar diameter.

Basically what's happening here is -
Because of the weak heart, it cannot efficiently pump all the blood it's receiving - which causes 'pooling' of the blood in the venous system - causing increased "venous pressure", increased "venous resistance" (which I assume is the resistance to blood offered by the venous system)

Now considering the capillary system. Below normal cardiac output in heart failure --> lesser quantity of blood reaches capillaries in unit time --> lower capillary flow.
The capillary hydrostatic pressure however will increase because of venous pooling of blood (as already explained) --> delayed clearance of blood from capillary to venous system (causing stagnation).
Note that capillary flow is determined by total amount of blood traversing the capillaries in unit time (eg. one minute)
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Old 02-17-2012
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Question

Quote:
Originally Posted by DNA 105 View Post
Not quite sure what "venous resistance" imply here. "Vascular resistance" would have been a much better term which basically implies the resistance offered by the arterioles to the blood being pumped - which obviously will be more in heart failure 'cause of the sympathetic surge and reduced arteriolar diameter.

Basically what's happening here is -
Because of the weak heart, it cannot efficiently pump all the blood it's receiving - which causes 'pooling' of the blood in the venous system - causing increased "venous pressure", increased "venous resistance" (which I assume is the resistance to blood offered by the venous system)

Now considering the capillary system. Below normal cardiac output in heart failure --> lesser quantity of blood reaches capillaries in unit time --> lower capillary flow.
The capillary hydrostatic pressure however will increase because of venous pooling of blood (as already explained) --> delayed clearance of blood from capillary to venous system (causing stagnation).
Note that capillary flow is determined by total amount of blood traversing the capillaries in unit time (eg. one minute)
Thanks for your note, one question remain and that is whether sympathetic system also affect venous system or not?
In Kaplan Physiology I also found that venous resistance in heart failure is not changed.
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Old 02-18-2012
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Default Yes.

Quote:
Originally Posted by Evergreen View Post
whether sympathetic system also affect venous system or not?
Of course it does. I've attached an image to give you an idea of the density of sympathetic supply to different parts of the circulation. You may note that almost all other vascular systems except capillaries are innervated.

Hope that helps.

Pressure, Flow, and Resistance in Heart Failure-slide1.jpg
click image to enlarge
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Old 05-20-2012
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Quote:
Originally Posted by Evergreen View Post
Why it's not B? Because of venous compliance, may be we don't have significant increase in venous resistance, although total vascular resistance is increased due to sympathetic tone in CHF.
the ans has to be b..
it makes perfect sense
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  #11  
Old 01-26-2013
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Default ans is b

b is the best answer
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