The Importance of Antidiuretic Hormone in the Human Body

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  • Topic: Vasopressin, Diabetes insipidus, Hypothalamus
  • Pages : 3 (751 words )
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  • Published : April 17, 2013
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Antidiuretic Hormone is a nanopeptide, meaning it has nine amino acids (Allain). The hormone is made in the hypothalamus and is transported by axons to be stored in the posterior lobe of the pituitary gland. From there, it is released into the blood circulation when necessary (Bowen). ADH regulates plasma osmolarity, or the concentration of solutes in the blood. Osmoreceptors are neurons that sense the osmolarity and send information to the hypothalamus. When plasma osmolarity is below a certain threshold, the osmoreceptors are not activated and the secretion of ADH is suppressed. When osmolarity increases above the threshold, the osmoreceptors stimulate the neurons that secrete ADH (Bowen). ADH is released from the hypothalamus when osmoreceptor cells in the hypothalamus detect a rise in blood osmolarity, which is normally caused by an excessive loss of water. It reaches the kidneys by blood vessels. Once at the kidneys, the hormone makes distal convoluted ducts more permeable to water so that more is reabsorbed and water is conserved in the blood. The juxtaglomerular apparatus, or JGA, helps the kidney when one has low blood pressure or low blood volume. When blood pressure drops or there is a lack of sodium in the blood, the JGA releases the enzyme renin into the bloodstream. Renin acts on the plasma protein angiotensin, and turns it into its active form, angiotensin II. Angiotensin II then constricts the arterioles, which raises blood pressure. Raising blood pressure in the arterioles increases filtration (“Hormones of Kidney Regulation”). Antidiuretic hormone has many disorders related to it. The most common disease of man and animals related to ADH is diabetes insipidus. Diabetes insipidus is a disorder characterized by intense thirst, despite the drinking of fluids, and the excretion of large amounts of urine. There are four main types of diabetes insipidus: hypothalamis diabetes insipidus, nephrogenis diabetes insipidus, gestational diabetes insipidus,...
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