Final answer:
The main site for sodium and chloride reabsorption in the nephron is the distal convoluted tubule and the collecting ducts. Sodium is actively transported out of the tubule in these segments, primarily under the influence of the hormone aldosterone.
Step-by-step explanation:
The main site for sodium and chloride reabsorption in the nephron is the distal convoluted tubule and the collecting ducts. Sodium is actively transported out of the tubule in these segments, primarily under the influence of the hormone aldosterone. The movement of sodium out of the lumen creates a negative charge, promoting the movement of chloride out of the lumen as well. This process helps in the reabsorption of sodium and chloride and contributes to maintaining proper electrolyte balance in the body.