Physio (Review): Kidney Solute Processing, Sodium And Water

Question 1

How do you calculate Filtration Fraction (FF)

Answer 1

FF = (GFR) / (RPF)

Question 2

Autoregulation

Answer 2

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

Question 3

Autoregulation becomes absent at MAP (mean arterial pressure) of ___________ mmHg

Answer 3

<70 mmHg

Question 4

Autoregulation is a completely _____________ process

Answer 4

Intrarenal

Question 5

What are the 2 mechanisms of autoregulation?

Answer 5

1. Myogenic mechanism

2. Tubuloglomerular feedback

Question 6

The Myogenic mechanism is intrinsic to the ____________ in the blood vessels

Answer 6

Vascular Smooth Muscle

Fast acting

Question 7

Myogenic mechanism protects the glomeruli from short term __________

Answer 7

Pressure changes

You get contraction of the vascular smooth muscle in response to increase STRETCH

Question 8

Increased blood pressure will increase passive wall tension….Which leads to an increase in ________

Answer 8

GFR and RPF

Question 9

The myogenic mechanism is via stretch-activated increased in ____________ influx in vascular smooth muscle

Answer 9

Ca2+

Question 10

A high GFR results in increased flow and increased Na+ delivery to the ______________

Answer 10

Macula Densa

The macula densa is part of the juxtaglomerular apparatus.

Senates flow and Na+ concentration

Question 11

High flow/Na+ = release of ____________

Answer 11

ATP and Adenosine

Question 12

Mesangial cell contraction = decreased_______________

Answer 12

Kf

Kf is the filtration coefficient

It is about equal to the glomerular surface area