In renal physiology, reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid (pre-urine) and returns them to the circulating blood.[1] It is called reabsorption (and not absorption) because these substances have already been absorbed once (particularly in the intestines) and the body is reclaiming them from a postglomerular fluid stream that is on its way to becoming urine (that is, they will soon be lost to the urine unless they are reabsorbed from the tubule into the peritubular capillaries. This happens as a result of sodium transport from the lumen into the blood by the Na+/K+ATPase in the basolateral membrane of the epithelial cells. Thus, the glomerular filtrate becomes more concentrated, which is one of the steps in forming urine. Nephrons are divided into five segments, with different segments responsible for reabsorbing different substances.[2] Reabsorption allows many useful solutes (primarily glucose and amino acids), salts and water that have passed through Bowman's capsule, to return to the circulation. These solutes are reabsorbed isotonically, in that the osmotic potential of the fluid leaving the proximal convoluted tubule is the same as that of the initial glomerular filtrate. However, glucose, amino acids, inorganic phosphate, and some other solutes are reabsorbed via secondary active transport through cotransport channels driven by the sodium gradient.
Locations of secretion and reabsorption in the nephron
reabsorption, confused, with, resorption, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article, needs, additional, citations, verification, please, help, impro. Not to be confused with Resorption This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Reabsorption news newspapers books scholar JSTOR April 2022 Learn how and when to remove this template message This article may be confusing or unclear to readers Please help clarify the article There might be a discussion about this on the talk page February 2007 Learn how and when to remove this template message Learn how and when to remove this template message In renal physiology reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid pre urine and returns them to the circulating blood 1 It is called reabsorption and not absorption because these substances have already been absorbed once particularly in the intestines and the body is reclaiming them from a postglomerular fluid stream that is on its way to becoming urine that is they will soon be lost to the urine unless they are reabsorbed from the tubule into the peritubular capillaries This happens as a result of sodium transport from the lumen into the blood by the Na K ATPase in the basolateral membrane of the epithelial cells Thus the glomerular filtrate becomes more concentrated which is one of the steps in forming urine Nephrons are divided into five segments with different segments responsible for reabsorbing different substances 2 Reabsorption allows many useful solutes primarily glucose and amino acids salts and water that have passed through Bowman s capsule to return to the circulation These solutes are reabsorbed isotonically in that the osmotic potential of the fluid leaving the proximal convoluted tubule is the same as that of the initial glomerular filtrate However glucose amino acids inorganic phosphate and some other solutes are reabsorbed via secondary active transport through cotransport channels driven by the sodium gradient Locations of secretion and reabsorption in the nephronRenin angiotensin system The kidneys sense low blood pressure Release renin into the blood Renin causes production of angiotensin I Angiotensin converting enzyme ACE converts angiotensin I to angiotensin II Angiotensin II stimulates the release of aldosterone ADH and thirst Aldosterone causes kidneys to reabsorb sodium ADH increases the uptake of water Water follows sodium As blood volume increases pressure also increases See also EditTransepithelial potential difference driving reabsorptionReferences Edit Skirving Mya Borger Pam Chiovtti Tony Duncan Jacinta Gerdtz Wayne Guay Patrick Jean Martin Genevieve Walker Katrina Woolnough Jim Wright Jane 2020 Chapter 11 Regulation of Water Salts and Gases In Attley Teresa Irwin Kirstie eds Biology WA ATAR Units 3 amp 4 1st ed South Melbourne Victoria Australia Cengage Learning Australia pp 374 402 ISBN 9780170452922 Tubular reabsorption article article Khan Academy Retrieved 2022 03 17 Retrieved from https en wikipedia org w index php title Reabsorption amp oldid 1175767845, wikipedia, wiki, book, books, library,
