Question

what is the main function of the loop of henle in the urine formation process?

Answer 1

actually, the function is a little more complex.

in the main part, compounds like glucose, amino acids and electrolytes are resorbed.

in the intermediate part, water is resorbed from the primary urine (else, you would pee about 180 liters a day!)

in the tubulus distalis, NaCl is resorbed thorugh Na+ ion channels

Answer 2

reabsobtion of water and NaCl from the urine thus making the resultant urine more concentrated.