Step I Total peripheral resistance and venous return

[Blakeb_212]

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Hey all,
I have a question in regards to cardiology.
If total peripheral resistance is increased, is the system increasing or decreasing venous return? And can I think of TPR and vasoconstriction/dilation as the same term?

Also if you have time, can you briefly look through the table (top two lines) and tell me if the trend is correct or not? Just wondering if it’s an accurate study guide.

Thanks grade savers!

 

[wanderingorion]

Increased TPR causes decreased venous return, as the blood is retained in the arterial vessels.

 

[Blakeb_212]

Increased TPR causes decreased venous return, as the blood is retained in the arterial vessels.

Thank you! I was getting confused because I found that vasoconstriction increases venous return but that must be because it is on the venue side

 

[FindersFee5]

Thank you! I was getting confused because I found that vasoconstriction increases venous return but that must be because it is on the venue side

I think it might be the terminology that's confusing here, vasoconstriction is constriction of the arteries and arterioles, venoconstriction is constriction of the venous system and is what increases VR. TPR is mostly determined by the arterioles, so changes in TPR are mostly changed by vasoconstriction. Venous tone (venoconstriction) controls VR.

 

[Blakeb_212]

I think it might be the terminology that's confusing here, vasoconstriction is constriction of the arteries and arterioles, venoconstriction is constriction of the venous system and is what increases VR. TPR is mostly determined by the arterioles, so changes in TPR are mostly changed by vasoconstriction. Venous tone (venoconstriction) controls VR.

That does help clarify! Thank you

 

[Instatewaiter]

Another way to think about it, increase TPR is the same as increased afterload on the heart.
This decreases cardiac output. Under steady state venous return and cardiac output are equivalent. So venous return should decrease when tpr (ie SVR in practice) increases