<prompt> Effect of efferent aeriole constriction and afferent aeriole dilatation on GFR is?IncreasesDecreasesNo changeFirst increase then decrease  <response>: Increases REF: Ganongs 22 chapter 38 Increase in renal blood flow increases GFR. Afferent aeriole brings blood to the nephron hence its dilation will increase renal blood flow, and efferent aeriole takes blood away from the nephrons, hence its constriction will cause increase filtration, hence increase in GFR. 