How is Concentrated Urine Produced?
The following steps are carried out to form concentrated urine:
- NaCl is transported to the descending limb of the vasa recta through the ascending limb of Loop of Henle.
- This leads to the formation of a concentration gradient that extends from 300 mm in the cortex to 1200 mm in the medulla.
- The space that lies between the vasa recta and the loop of Henle is known as the interstitium.
- The descending limb of the loop of Henle carries urea to the interstitium.
- Urine encounters increasing solute concentrations in the interstitium as it travels lower in the collecting tubule. It thus keeps losing water as a result of osmosis.
- Through the vasa recta, absorbed water is reintroduced into the circulatory system. Any solutes that are reabsorbed into the bloodstream have time to diffuse back into the interstitial fluid because of the extremely slow blood flow in these capillaries, maintaining the gradient in solute concentration in the medulla.
- The ADH or the Antidiuretic hormone regulates urine concentration and aids in water conservation for the kidneys. Its primary effect in the renal tubules is to increase the osmotic gradient by increasing water permeability in the collecting ducts and late distal tubule. It also increases sodium chloride active transport in the thick ascending limb of the loop of Henle, and enhances urea recycling and countercurrent multiplication.
Also Read: Difference Between Osmosis and Diffusion
Countercurrent Mechanism – Urine Formation and Steps
The countercurrent mechanism in kidney is a process of concentrating urine. It involves the flow of filtrate in opposite directions in the two limbs of the loop of Henle, which creates an osmotic gradient. This gradient allows the kidneys to reabsorb water from the filtrate and produce concentrated urine.
In this article, we will discuss more about the countercurrent mechanism, the steps involved, how urine is formed, and the multiplication of the countercurrent. You can also find the countercurrent mechanism notes here.
Table of Content
- What are the Countercurrent Mechanisms?
- Where Does the Counter-Current Mechanism of Urine Formation Occur?
- Countercurrent Mechanism Steps
- Countercurrent Mechanism Diagram
- What is Countercurrent Exchange Multiplication?
- How is Concentrated Urine Produced?
- Importance of Counter Current Mechanism
Contact Us