Is the descending limb of the loop of henle impermeable to ions?Watch
The descending limb is highly permeable to water but impermeable to ions, e.g. Na+, K+, Cl-. The ascending limb is highly permeable to ions and almost impermeable (but still a bit permeable) to water.
Do Sodium and chlorine ions move out of the ascending limb into decending limb? If so how can in move into descending limb if it's impermeable
The nephron is a three-dimensional structure that is surrounded by interstitial fluid, and there is a blood vessel called the vasa recta, which is where the solutes from the nephron are reabsorbed into:
This shows what is reabsorbed where from the loop of Henle:
So the contents of the nephron (the filtrate) moves freely from the descending limb to the ascending limb, but not all constituents of the filtrate can be reabsorbed from each area of the loop of Henle into the interstitial fluid (surrounding the nephron).
Hope this makes sense.