<prompt> Answer this question truthfullyWhat percentage of the filtered Na is normally reabsorbed by the thick ascending limb of Henle in the kidney?  <response>: <reason> The thick ascending limb of Henle is responsible for reabsorbing approximately 10-20 of the filtered Na in the kidney. This segment of the nephron plays a crucial role in the regulation of electrolyte balance and blood pressure by actively transporting Na ions out of the lumen of the tubule and into the interstitial fluid. The reabsorption of Na by the thick ascending limb is facilitated by the presence of specialized transporters in the cell membranes of the tubule cells, such as the NaK2Cl- cotransporter. This process is driven by the energy stored in ATP molecules and is tightly regulated by various hormones and signaling molecules in the body. 