<P> Firstly , the glucose in the proximal tubule is co-transported with sodium ions into the proximal convoluted tubule walls via the SGLT2 cotransporter . Some ( typically smaller ) amino acids are also transported in this way . Once in the tubule wall , the glucose and amino acids diffuse directly into the blood capillaries along a concentration gradient . This blood is flowing , so the gradient is maintained . Lastly , sodium / potassium ion active transport pumps remove sodium from the tubule wall and the sodium is put back into the blood . This maintains a sodium concentration gradient in the proximal tubule lining , so the first step continues to happen . </P>
<P> Firstly , the glucose in the proximal tubule is co-transported with sodium ions into the proximal convoluted tubule walls via the SGLT2 cotransporter . Some ( typically smaller ) amino acids are also transported in this way . Once in the tubule wall , the glucose and amino acids diffuse directly into the blood capillaries along a concentration gradient . This blood is flowing , so the gradient is maintained . Lastly , sodium / potassium ion active transport pumps remove sodium from the tubule wall and the sodium is put back into the blood . This maintains a sodium concentration gradient in the proximal tubule lining , so the first step continues to happen . </P>
where does primary active transport of sodium occur in the proximal convoluted tubule cells
where does primary active transport of sodium occur in the proximal convoluted tubule cells
walls
walls