Question

Which part of Henle's loop is impermeable to water but allows transports of electrolytes?

Answer 1

The loop has a sharp bend in the renal medulla going from descending to ascending thin limb. The thick ascending limb is impermeable to water, but it is permeable to ions. Sodium (Na+), potassium (K+) and chloride (Cl−) ions are reabsorbed from the urine by secondary active transport by a Na-K-Cl cotransporter (NKCC2).