Question

Explain how the direct renal mechanism counteracts an increase in blood pressure.

Answer 1

Blood is filtered at the glomerulus. This filtrate contains sodium, water and other substances. As the filtrate travels through the proximal tubule, loop of Henle, distal and collecting tubules, the concentration ofsodium is altered by transport of sodium across the tubular wall and into the renal interstitium, where it can diffuse into a dense network of intrarenal capillaries. Some of the renal tubules are permeable to water, so water leaves those tubular regions along with the sodium.