Intrinsic Control of Glomerular Filtration Rate

Intrinsic control of GFR is basically the kidneys fixing their own problems so the filtration

rate stays normal. They use two main tricks. First is the myogenic mechanism.

When your blood pressure suddenly goes up, the afferent arteriole stretches,

freaks out a little, and squeezes itself tighter so GFR doesn’t get too high. If blood pressure

drops, the arteriole relaxes and opens wider to bring GFR back up.

Second is tubuloglomerular feedback. This one listens to how much sodium reaches the macula

densa. If GFR is high, the filtrate is rushing through too fast,

so a lot of sodium shows up. The macula densa sees this and releases adenosine,