ANATOMY

Detailed explanation-1: -Under normal circumstances, up to 180 g/day of glucose is filtered by the renal glomerulus and virtually all of it is subsequently reabsorbed in the proximal convoluted tubule. This reabsorption is effected by two sodium-dependent glucose cotransporter (SGLT) proteins.

Detailed explanation-2: -Most of the glucose entering the tubular system is reabsorbed along the nephron segments, primarily in the proximal tubule, such that urine is almost free of glucose.

Detailed explanation-3: -The proximal tubules reabsorb about 65% of water, sodium, potassium and chloride, 100% of glucose, 100% amino acids, and 85-90% of bicarbonate. This reabsorption occurs due to the presence of channels on the basolateral (facing the interstitium) and apical membranes (facing the tubular lumen).

Detailed explanation-4: -The majority of solute and water reabsorption occurs in the proximal convoluted tubule. Sodium ions, which are the most plentiful cation (positively charged ion) in the tubular fluid, participate in most solute reabsorption.