GENERAL HISTOLOGY

Detailed explanation-1: -The thick descending limb of the Loop of Henle expresses a sodium-potassium-chloride cotransporter and this helps to reabsorb approximately one-third of the filtered sodium and chloride from the fluid in the tubular lumen into the blood.

Detailed explanation-2: -Typically, 99% of sodium ions which pass through the glomerulus are reabsorbed, however urinary osmolality and excretion volume can vary significantly in order to regulate sodium balance.

Detailed explanation-3: -The descending limb is highly permeable to water, with reabsorption occurring passively via aquaporin-1 (AQP1) channels. Small amounts of urea, sodium (Na+) and other ions are also reabsorbed.