Читать книгу Understanding Anatomy and Physiology in Nursing - John Knight - Страница 129

The term antidiuretic hormone is applied to this hormone since its major effect is to reduce urine output by the kidneys, leading to the production of dark, concentrated urine (Chapter 11). When BP is low this is an ideal strategy, since by reducing urine production more water remains in the blood, boosting plasma volume and increasing BP. ADH further increases BP by stimulating arterial vasoconstriction.

Conversely, when the aortic arch and carotid sinus baroreceptors detect an increase in BP the release of ADH from the posterior pituitary is reduced or stopped. This leads to the production of a large volume of dilute urine, effectively allowing the body to ‘dump’ blood volume in the form of dilute urine to reduce BP. Simultaneously, reduced levels of ADH will reduce arterial vasoconstriction to further reduce BP.