Loop of Henle in the Kidney?

In the kidney, the loop of Henle (or Henle's loop or ansa nephroni) is the portion of the nephron that leads from the proximal straight tubule to the distal convoluted tubule. The loop has a hairpin bend in the renal medulla. The main function of this structure is to create a concentration gradient in the medulla of the kidney. By means of a countercurrent multiplier system, which utilizes sodium pumps, it creates an area of high sodium concentration deep in the medulla, near the collecting duct. Water present in the filtrate in the collecting duct flows through aquaporin channels out of the collecting duct, moving passively down its concentration gradient. This process reabsorbs water and creates a concentrated urine for excretion. It is named after its discovery by F. G. J. Henle.

The Loop of Henle causes urine to become more concentrated, and less dilute. Here's how it works:

In the Counter-Current exchange system, the Proximal convoluted tubule(PCT) and Descending limb of Henle are permeable to water, so this moves water OUT of the tubule. As water goes out of the tubule, the remaining fluid inside becomes more concentrated(less water, more solutes).
Then the Distal convoluted tubule(DCT) and Ascending limb of henle are impermeable to water (NOT allow water in). So since it's impermeable to water, then it is permeable to solutes( ions, suchas Sodium ions). So, then sodium/ions are pumped out. As a result,the Loop of Henle recovers more fluid than ions.

Basically, The Loop of Henle sets up a gradient where fluid becomes more concentrated (4 times more concentrated than usual). The DCT is normally 300 mOsm and as fluid(urine) goes down the DCT and into the Collecting Duct(CD), the fluid or urine becomes more concnetrated. (example- from 300mosm to 600mosm to 900mosm to1200mosm) (Multiplies by 4 each time).So urine becomes 4 times more concentrated as go DOWN.

Also, ADH (anti-diuretic hormone) also called "Vasopressin" effects the DCT and CD by increasing water permeability (allows water to move out of the CD), so as water leaves the fluid becomes more concentrated. Please note that ADH conserves water. This is how I think of it: if ADH conserves water Inside, then there's going to be less water out. If less water excreted out into the urine, then the urine will be more concentrated and less diluted.