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 Nephron plasma flow  

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Hello all,

I am very confused over one aspect of renal physiology - information in table does not make sense to me. At least not today.

If we constrict efferent arteriole and therefore our GFR goes up (because the pressure goes up) - how it is possible that nephron plasma flow goes down?
Is nephron plasma flow referred to plasma filtrate in nephron?

Many thanks smiling face


Think of the efferent arteriole as any arteriole in the body- when it constricts less blood goes through, hence decreased blood flow. This constriction also increases hydrostatic pressure before that point and thus increases filtration (starling forces).
Applied to your question: the constricted arteriole increased hydrostatic pressure in the glomerulus which lead to increased filtration. However, increased resistance caused by that constriction lead to decreased flow. As per Q= P/R. ( the essence really is that the constriction caused decreased volume of blood flow, but increased the fraction of that volume that is filtrated)

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