6) A decrease in MAP is detected by baroreceptors, whichinitiate a reflexive increase in sympathetic
activity. This results in generalized vasoconstriction ofarterioles throughout the body. Among the
arterioles that constrict are the afferent arterioles of thekidneys (which are innervated to a much
greater extent than the efferent arterioles). What effect does thishave on GFR? And how does this
counteract the drop in blood pressure? What is the consequence ofsympathetic stimulation of the beta-
1 receptors on JG cells?
