Final answer:
The majority of the reabsorption of the glomerular filtrate occurs in the proximal convoluted tubule (PCT) of the nephron, which is responsible for reclaiming water, salts, and organic solutes from the filtrate back into the blood.
Step-by-step explanation:
The majority of reabsorption of the glomerular filtrate occurs in the proximal convoluted tubule (PCT). This stage of nephron function involves the reabsorption of filtered salts, water, and all of the filtered organic solutes such as glucose and amino acids back into the blood. The process continues in the loop of Henle, where further water reabsorption occurs. While tubular reabsorption is a significant process in the proximal convoluted tubule, it is important not to confuse it with tubular secretion, which is the process where additional solutes and wastes are excreted into the tubules of the kidney. Overall, approximately two-thirds of the filtrate is reabsorbed at this initial segment of the renal tubule.