What is the countercurrent mechanism in the nephron?
The counter-current multiplier or the countercurrent mechanism is used to concentrate urine in the kidneys by the nephrons of the human excretory system. The nephrons involved in the formation of concentrated urine extend all the way from the cortex of the kidney to the medulla and are accompanied by vasa recta.
What is counter current in kidney?
A mechanism used by the kidneys, making it possible to excrete excess solutes in the urine with little loss of water from the body. When the filtrate runs in two different directions in the two arms of Henle’s loop, this is known as countercurrent.
How does the countercurrent mechanism in the nephron loop work?
The loop of Henle utilizes the countercurrent multiplier system to increase the concentration of solute and ions within the interstitium of the medulla. This ultimately allows the nephron to reabsorb more water and concentrate the urine while at the same time using as little energy as possible.
In what parts of the nephron does countercurrent multiplication take place?
Countercurrent multiplication was originally studied as a mechanism whereby urine is concentrated in the nephron. The thick ascending limb of the loop of Henle is the only part of the nephron lacking in aquaporin—a common transporter protein for water channels. This makes the thick ascending limb impermeable to water.
What is the significance of counter current mechanism?
Countercurrent multiplication in the kidneys is the process of using energy to generate an osmotic gradient that enables you to reabsorb water from the tubular fluid and produce concentrated urine.
Why it is called counter current mechanism?
Because the blood flow through these capillaries is very slow, any solutes that are reabsorbed into the bloodstream have time to diffuse back into the interstitial fluid, which maintains the solute concentration gradient in the medulla. This passive process is known as countercurrent exchange.
What do collecting ducts do?
The last part of a long, twisting tube that collects urine from the nephrons (cellular structures in the kidney that filter blood and form urine) and moves it into the renal pelvis and ureters. Also called renal collecting tubule.
What is the meaning of counter current flow?
Countercurrent flow can be defined as the two-phase flow regime in which the working fluids flow in opposite directions. One of the important interactions between these fluids is drag at which drag force acts opposite to the relative motion of the one fluid with respect to the other fluid.
What is a counter current multiplier system?
countercurrent multiplier system An active process occurring in the loops of Henle in the kidney, which is responsible for the production of concentrated urine in the collecting ducts of the nephrons.
What is a countercurrent exchange system?
Countercurrent exchange is a mechanism occurring in nature and mimicked in industry and engineering, in which there is a crossover of some property, usually heat or some chemical, between two flowing bodies flowing in opposite directions to each other.