Various substances influence blood pressure

Various substances influence blood pressure - lowers blood...

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Various substances influence blood pressure. Some important examples  follow: Epinephrine and norepinephrine, hormones secreted by the adrenal medulla,  raise blood pressure by increasing heart rate and the contractility of the heart  muscles and by causing vasoconstriction of arteries and veins. These  hormones are secreted as part of the fight-or-flight response. Antidiuretic hormone (ADH), a hormone produced by the hypothalamus and  released by the posterior pituitary, raises blood pressure by stimulating the  kidneys to retain H 2 O (raising blood pressure by increasing blood volume).  Atrial natriuretic peptide (ANP), a hormone secreted by the atria of the heart, 
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Unformatted text preview: lowers blood pressure by causing vasodilation and by stimulating the kidneys to excrete more water and Na + (lowering blood pressure by reducing blood volume). Nitric oxide (NO), secreted by endothelial cells, causes vasodilation. Nicotine in tobacco raises blood pressure by stimulating sympathetic neurons to increase vasoconstriction and by stimulating the adrenal medulla to increase secretion of epinephrine and norepinephrine. Alcohol lowers blood pressure by inhibiting the vasomotor center (causing vasodilation) and by inhibiting the release of ADH (increasing H 2 O output, which decreases blood volume)....
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