As a part of the urea recycling process, in order for the concentration gradient to be maintained, it is important that urea makes up about of the solutes of the interstitial fluid concentration gradient.

As a part of the urea recycling process, in order for the concentration gradient to be maintained, it is important that urea makes up about approximately one-half of the solutes of the interstitial fluid concentration gradient. Urea is detached from the fluid-tube in the gathering duct by urea uniporters; it spreads back in the fluid-tube in the thin part of the rising limb. Urea is cycled among the tubule collectors and loop in the nephron.

the glands which are associated with each description is given below: