Physio (Review): Kidney Solute Processing, Sodium And Water Flashcards
How do you calculate Filtration Fraction (FF)
FF = (GFR) / (RPF)
Autoregulation
Critical for the kidneys to keep GFR within a limited range
Arterial pressure fluctuations (80-180 mmHg) result in only small changes in GFR and RPF
Autoregulation becomes absent at MAP (mean arterial pressure) of ___________ mmHg
<70 mmHg
Autoregulation is a completely _____________ process
Intrarenal
What are the 2 mechanisms of autoregulation?
- Myogenic mechanism
2. Tubuloglomerular feedback
The Myogenic mechanism is intrinsic to the ____________ in the blood vessels
Vascular Smooth Muscle
Fast acting
Myogenic mechanism protects the glomeruli from short term __________
Pressure changes
You get contraction of the vascular smooth muscle in response to increase STRETCH
Increased blood pressure will increase passive wall tension….Which leads to an increase in ________
GFR and RPF
The myogenic mechanism is via stretch-activated increased in ____________ influx in vascular smooth muscle
Ca2+
A high GFR results in increased flow and increased Na+ delivery to the ______________
Macula Densa
The macula densa is part of the juxtaglomerular apparatus.
Senates flow and Na+ concentration
High flow/Na+ = release of ____________
ATP and Adenosine
Mesangial cell contraction = decreased_______________
Kf
Kf is the filtration coefficient
It is about equal to the glomerular surface area