Kidney filtration: Autoregulation, RAAS & sympathetic control

The kidneys must keep filtration remarkably constant despite continuous changes in blood pressure and blood volume. How do they maintain a stable glomerular filtration rate (GFR) while still responding appropriately to dehydration, haemorrhage and other physiological stresses? In this lecture, we explore the mechanisms that regulate GFR, including autoregulation, the myogenic response, tubuloglomerular feedback, the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system control. We also examine how the kidneys respond to mild and severe reductions in blood pressure, balancing the need to maintain filtration with the need to preserve circulation and survival.