Dual Juxtaglomerular Feedback Mechanism

Dual Juxtaglomerular Feedback Mechanism

To the tune of “My Favourite Things” from The Sound of Music

[Verse 1]
The juxtaglomerular apparatus
Senses low sodium which is symptomatic
Of a reduced glomerular flow rate
JG cells secrete renin to compensate

 [Verse 2]
Renin eventually leads to the production
Of angiotensin II and its main action
It constricts the efferent arterioles
Increasing the rate of glomerular blood flow

[Chorus] 
The JG cells
They will act
Through negative feedback
This mechanism helps to maintain
Homeostatic effects

[Verse 1] 
A reduction in mean arterial pressure
Slows the glomerular flow rate for good measure
This slows the flow rate in the loop of Henle
Sodium chloride absorption is increased

[Verse 2] 
Macula densa receives less NaCl
ATP is secreted at lower levels
It’s typically converted to adenosine
The levels of which in plasma will decrease

[Verse 3] 
A low adenosine concentration
Causes afferent arteriole dilation
This raises the glomerular flow rate
A mechanism to compensate

[Chorus] 
Macula densa
Cells will act
Through negative feedback
This mechanism helps to maintain
Homeostatic effects