Under normal conditions, maximum reabsorption takes place in __ of nephron.

The Proximal Convoluted Tubule (PCT) of the nephron is responsible for the effective reabsorption of crucial substances from the filtrate during urine formation. Positioned after the glomerulus and Bowman's capsule, the PCT's specialised structure, featuring a microvilli-covered brush border, maximises its surface area for absorption.

In the PCT, a combination of active and passive transport mechanisms facilitates reabsorption. Key nutrients like glucose and amino acids are actively transported into PCT cells through specialised carriers, preventing their loss in urine. Sodium ions (Na⁺) are actively transported out of PCT cells, establishing an osmotic gradient that drives passive water reabsorption, regulating fluid balance.

Additionally, the PCT regulates the reabsorption of various ions, including potassium, bicarbonate, and calcium, contributing to electrolyte equilibrium. As the filtrate exits the PCT, a substantial portion of water, nutrients, and solutes have been reclaimed.