Chapter 23.4, Problem 3AYLO

Summary Introduction

To discuss:

How the PCT reabsorbs NaCl, other electrolytes, glucose, urea, and water; why the reabsorption of water and solutes depends directly or indirectly on the sodium-glucose transporter (SGLT) and sodium reabsorption.                     

Introduction:

In the whole of the glomerular filtrate, about 65% are reabsorbed by the proximal convoluted tubule. The proximal convoluted tubule removes wastes present in the blood and excretes them through the urine. Due to the presence of microvilli (its greater length), the proximal convoluted tubule has the benefits of increasing its surface area for absorption. Proximal convoluted tubule cells are equipped with a rich source of large mitochondria that produce ATP, which supports active transport. Of all the calories that are consumed in a day, only 6% of ATP is needed by the proximal convoluted tubule.