<P> Most of the reabsorption ( 65 % ) occurs in the proximal tubule . In the latter part it is favoured by an electrochemical driving force , but initially it needs the cotransporter SGLT and the Na - H antiporter . Sodium passes along an electrochemical gradient ( passive transport ) from the lumen into the tubular cell , together with water and chloride which also diffuse passively . Water is reabsorbed to the same degree , resulting in the concentration in the end of the proximal tubule being the same as in the beginning . In other words , the reabsorption in the proximal tubule is isosmotic . </P>
<P> Most of the reabsorption ( 65 % ) occurs in the proximal tubule . In the latter part it is favoured by an electrochemical driving force , but initially it needs the cotransporter SGLT and the Na - H antiporter . Sodium passes along an electrochemical gradient ( passive transport ) from the lumen into the tubular cell , together with water and chloride which also diffuse passively . Water is reabsorbed to the same degree , resulting in the concentration in the end of the proximal tubule being the same as in the beginning . In other words , the reabsorption in the proximal tubule is isosmotic . </P>
where is most sodium reabsorbed in the kidney
where is most sodium reabsorbed in the kidney
the proximal tubule
the proximal tubule