Hormones in body fluid homestasis (ADH/vasopressin, Aldosterone and Natriuretic peptides)

hello in this video we're going to talk about hormones of fluid balance or fluid homeostasis three hormones mediate physiological adjustments in fluid balance and electrolyte balance these are aldosterone antidiuretic hormone also known as arginine vasopressin and the natural peptides a MP and BNP these hormones are released from endocrine organs or glands and travel in blood the main source of water is from the gastrointestinal tract when we drink the main way we secrete fluid is through urine these hormones that maintain fluid balance mainly affect the kidneys and so we need to revise the functional unit of the kidneys which are the nephrons where these hormones act on here is the nephron the head of the nephron is the Bowman's capsule here is a proximal convoluted tubules the loop of Henle the distal convoluted tubules and the collecting duct fluid enters the head of the nephron via the afferent artery and forms the glomerulus the glomerulus then exits the Bowman's capsule to form the Vasa recta here in orange which secretes and reabsorbed solutes along the renal tubular so starting from the head of the nephron water gets filtered through water in the tube of the nephron gets reabsorbed mainly in the proximal convoluted tubule through aquaporin type one channels this is ninety percent of the water the remaining 10% is at the distal convoluted tubules and the collecting duct which is primarily driven by the hormone ADH this 10% is reabsorbed back into circulation via aquaporin type two channels which are primarily driven by the hormone ADH so where does ADH come from well ADH is secreted by the posterior pituitary gland however ADH is actually produced by the hypothalamus in response to an increase in plasma osmolarity or a decrease in blood volume an increase in plasma osmolarity basically means when you have high solute levels in the blood and respect to water sodium is a strong stimulant here if sodium levels are high and if the blood volume is low it will stimulate the hypothalamus to produce ADH which will then travel to the posterior pituitary to be released into circulation ADH is also known as arginine vasopressin ATH travels to the nephron to the distal convoluted tubule a collecting duct where it will stimulate the expression of aquaporin type two channels to reabsorb more water back into circulation in summary ath targets the distal convoluted tubules and the collecting ducts of the nephron it increases aquaporin type 2 channels which increases water reabsorption and so increases fluid volume and also decreases plasma osmolarity ADH also has an effect on peripheral resistant there are ADH receptors on blood vessels when ADH binds it can cause vasoconstriction which increases peripheral resistance and soaking increased blood pressure however ADH role in major constriction is mainly during a lot of blood loss the next hormone which is important in maintaining blood volume fluid homeostasis is aldosterone a mineral corticoid which is released by the adrenal cortex of the adrenal gland how does adult stir and get released and what does it do when you have low blood volume or low blood pressure it will stimulate the renin-angiotensin-aldosterone system or wrasse for short rass stimulates essentially will lead to the stimulation of aldosterone from the adrenal cortex hyperkalemia high potassium levels and low serum sodium levels can also directly stimulate aldosterone release into circulation aldosterone is a mineral corticoid and thus bind onto a transport protein in circulation mainly albumin but also transport in a protein also produced by the liver aldosterone travels to the distal Convertible of the nephron here it increases the expression of Enoch and sodium potassium ATPase pumps what this means is that aldosterone will essentially result in the read uptake of sodium from the nephron to Buhl into circulation and as a general rule water will follow sodium and so you eat you increase the reabsorption of water as well so in summary aldosterone targets distal convoluted tubules where it will increase Enoch channels and sodium potassium ATPase which will lead to sodium reabsorption and therefore water retention which will increase fluid volume and also decrease serum potassium at the same time the final hormone in maintaining blood volume and fluid emesis is the natural peptides we have the opposite effects of ADH and of aldosterone the natural addict peptides are released by the heart specifically the atrium and the ventricle naturally peptides have opposite effects of ADH and aldosterone and so the trigger of its release differs high blood pressure and high blood volume will cause stretching of the heart wall which will trigger the release of ANP and BNP am/pm BMP are your natural peptides and they will inhibit the activity of aldosterone and they will do this in a few ways one they will decrease sympathetic activity which will inhibit essentially the release of renin and so will inhibit the renin-angiotensin-aldosterone system altogether naturally peptides also caused afferent arterial vasodilation which will increase glomerular filtration rate when you increase the glomerular filtration rate this will tell the juxtaglomerular cells at the head of the nephron to stop releasing renin and so will it inhibit the renin-angiotensin-aldosterone system altogether as well finally the naturally peptides also have a role in blood vessels it has the opposite effect to the antidiuretic hormone the naturally peptide binds on to naturally peptide receptors on vessels causing vasodilation which will lead to a reduction in peripheral resistance which means it will also decrease blood pressure you

Channel: Armando Hasudungan

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Keywords: Aldosterone physiology, antidiuretic hormone physiology, nartiuretic peptides physiology, posterior pituitary hormones, adrenal gland hormones and physiology, heart hormones, ANP and BNP physiology, fluid balance and homeostasis

Id: FzeL1fcBwnE

Length: 7min 51sec (471 seconds)

Published: Mon Sep 24 2018