Final answer:
Epinephrine and norepinephrine are the "fight or flight" hormones that are released by the adrenal medulla and the nervous system, respectively. They constrict the blood vessels, including the afferent arterioles, which stops the flow of blood into the nephrons.
Step-by-step explanation:
Epinephrine and norepinephrine are the "fight or flight" hormones that are released by the adrenal medulla and the nervous system, respectively, under extreme stress. These hormones constrict the smooth muscles of the blood vessels. They constrict the afferent arterioles, causing the flow of blood into the nephrons to stop.