Dual Juxtaglomerular Feedback Mechanism

To the tune of "My Favourite Things" from The Sound of Music
The juxtaglomerular apparatus
Senses low sodium which is symptomatic
Of a reduced glomerular flow rate
JG cells secrete renin to compensate
Renin eventually leads to the production
Of angiotensin II and its main action
It constricts the efferent arteriole
Increasing the rate of glomerular blood flow
The JG cells
They will act
Through negative feedback
This mechanism helps to maintain
Homeostatic effects
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
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
A low adenosine concentration
Causes afferent arteriole dilation
This raises the glomerular flow rate
A mechanism to compensate
Macula densa
Cells will act
Through negative feedback
This mechanism helps to maintain
Homeostatic effects