Final answer:
The false statement regarding potassium secretion is that it occurs in the medullary collecting duct, as the primary site is in the distal convoluted tubule and collecting duct. Additionally, increased potassium secretion is not paired with sodium reabsorption, which is also false.
Step-by-step explanation:
The false statement regarding potassium secretion is that it occurs in the medullary collecting duct. In fact, potassium secretion primarily occurs in the distal convoluted tubule and collecting duct. To elaborate, here are the truths regarding potassium secretion: Hyperkalemia indeed leads to an increase in K+ secretion to maintain homeostasis; an increase in the activity of the Na/K pump will also result in greater K+ secretion; potassium secretion is typically paired with sodium reabsorption, influenced by aldosterone, which promotes Na+ reabsorption and K+ secretion. Therefore, the second false statement among the options provided is that increased potassium secretion is paired with sodium reabsorption; instead, potassium secretion usually takes place whenever sodium is reabsorbed.