Venous Circulation

[Dr Gerrard]

I recently did a Kaplan Section Test, BS test 6.

The explanation to one question said that skeletal muscle assists with venous circulation.

But I know that all skeletal muscle is voluntary and thus is not regulated by the autonomic nervous system.

I would have guessed that smooth muscle assisted with venous circulation.

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[capn jazz]

Nope, it's skeletal: http://en.wikipedia.org/wiki/Skeletal-muscle_pump

It's not an automatic thing, it's just a side effect of the fact that when you are moving the contraction/relaxation of your skeletal muscles in your legs for instance squeezes the veins and helps with venous return. That's why people sometimes faint when shadowing a surgeon or something similar because standing still for so long reduces the venous return to the heart.

 

[FutureInternist]

And why people should walk around & stretch their legs when on long international flights....Don't want any DVTs

 

[absolute8]

I recently did a Kaplan Section Test, BS test 6.

The explanation to one question said that skeletal muscle assists with venous circulation.

But I know that all skeletal muscle is voluntary and thus is not regulated by the autonomic nervous system.

I would have guessed that smooth muscle assisted with venous circulation.

skeletal muscles act as pumps to help move the blood in veins that have one way valves- this muscle is helping with venous return, hence with the venous cirucation. This whole concept relates to the physiological concept of "cardiac output" if you want to look up more on it.

 

[thebillsfan]

i think i read somewhere that there IS some smooth muscle in the venous system to help with vasoconstriction/dilation. is that true?

 

[capn jazz]

All arteries/veins are lined with smooth muscle as far as I know.

 

[G1SG2]

I recently did a Kaplan Section Test, BS test 6.

The explanation to one question said that skeletal muscle assists with venous circulation.

But I know that all skeletal muscle is voluntary and thus is not regulated by the autonomic nervous system.

I would have guessed that smooth muscle assisted with venous circulation.

Think about those guards with the red coats and black hats and how they stomp their feet hard before walking off duty-the muscle contraction in their legs helps to squeeze all that blood up from the legs since they have not been walking around, and prevents them from fainting if they had just started walking without stomping their feet. Since pressure is low in the veins, the contraction of skeletal muscle in the legs sort of squeezes the veins and helps to push the blood along. It's definitely skeletal muscle.

 

[MCATBear]

To be completely unscientific about it, this is what people mean when they say you should stand up and walk around and get your blood flowing. People do say that right? It's not just my mom?

 

[G1SG2]

To be completely unscientific about it, this is what people mean when they say you should stand up and walk around and get your blood flowing. People do say that right? It's not just my mom?

haha, yes.