How does renal artery constriction maintain a constant glomerular filtration rate (GFR) in an experiment where the arcuate artery pressure is decreased?

In situations where there is a decrease in the pressure at the arcuate artery, the kidneys can maintain a relatively constant glomerular filtration rate (GFR) by adjusting the resistance in the afferent and efferent arterioles. Specifically, increased resistance in the efferent arterioles helps to counteract the reduced pressure in the afferent arterioles, thereby maintaining glomerular filtration.

When the efferent arterioles constrict, it effectively increases the pressure within the glomerulus, which counters the reductions in pressure that occur due to the decreased arcuate artery pressure. This elevated pressure within the glomeruli helps preserve the GFR even when renal perfusion pressure decreases. The body employs this mechanism as part of the myogenic response and tubuloglomerular feedback to regulate renal blood flow and glomerular filtration efficiently, ensuring that the kidneys can continue to function properly even in the face of fluctuating blood supply.

By contrast, increased resistance in the afferent arterioles would reduce blood flow into the glomerulus, making it harder to maintain a stable GFR. The glomerular filtration coefficient pertains to the surface area and permeability of the glomerular membrane, which is not directly