Final answer:
The cortical collecting tubule in the kidney is regulated by aldosterone and ADH. Aldosterone stimulates sodium reabsorption, while ADH regulates water reabsorption.
Step-by-step explanation:
The cortical collecting tubule in the kidney is regulated by various mechanisms and hormones. The hormone aldosterone, produced by the adrenal glands, plays a key role in regulating sodium and water reabsorption in the cortical collecting tubule. Aldosterone stimulates the insertion of sodium channels into the membrane of the tubule cells, increasing sodium reabsorption and water retention. Another hormone, antidiuretic hormone (ADH), also known as vasopressin, regulates the reabsorption of water in the collecting tubule by stimulating the insertion of water channels called aquaporins into the tubule cells.