Final answer:
True, water reabsorption in the PCT is obligatory, following the active reabsorption of sodium, while in the DCT, it's facultative and regulated by hormones like aldosterone and ADH.
Step-by-step explanation:
The statement that water reabsorption through the proximal convoluted tubule (PCT) is termed obligatory water reabsorption, whereas water reabsorption through the distal convoluted tubule (DCT) is termed facultative water reabsorption is True. Obligatory water reabsorption occurs because water is "obliged" to follow sodium (Na+) as it is actively pumped out of the PCT into the peritubular capillaries. In contrast, in the DCT and collecting ducts, the reabsorption of water is regulated by hormones such as aldosterone, which increases Na+/K+ ATPase activity, and antidiuretic hormone (ADH), which allows the body to retain water as needed, making this process facultative.
In the proximal convoluted tubule, the presence of aquaporins allows water to be reabsorbed independently, due to the low blood pressure and high osmotic pressure in the peritubular capillaries. In the distal convoluted tubule and collecting ducts, regulated reabsorption involves hormonal control and is responsible for the balance of water and mineral salts in the blood.