In the ______, 60 to 80% of the potassium in the tubular fluid is reabsorbed.Multiple choice question.CTPCTDCTCD

The correct answer is CTD (Cortical Thick Ascending Limb of the Loop of Henle).

Explanation

In the renal system, particularly in the nephron, potassium (K⁺) plays a crucial role in maintaining electrolyte balance. The reabsorption of potassium primarily occurs in two segments of the nephron: the proximal convoluted tubule (PCT) and the cortical thick ascending limb (CTD) of the loop of Henle.

In the CTD, approximately 60 to 80% of potassium found in the tubular fluid is reabsorbed back into the bloodstream. This reabsorption process is essential as it helps regulate electrolyte levels and prevent excessive loss of potassium, which can lead to serious health issues. The chloride-potassium-sodium co-transporter (NKCC2) facilitates this process by actively transporting potassium ions alongside sodium and chloride ions. This selective reabsorption is vital for maintaining the osmotic balance and overall fluid homeostasis in the body.

In summary, the reabsorption of potassium within the CTD is a key physiological mechanism to ensure that sufficient levels of potassium are retained, thereby supporting numerous cellular functions and overall health.