Physiology The primary active step for sodium reabsorption in the proximal tubule involves: A Sodium-glucose cotranspo across the luminal membrane B Sodium/hydrogen ion counteranspo across the luminal membrane C Sodium transpo the Na+-K+-ATPase at the basolateral membrane D Sodium-amino acid cotranspo across the luminal membrane 💡 Explanation The primary active step for sodium reabsorption in the proximal tubule involves: ✓ Correct Answer: C. Sodium transpo the Na+-K+-ATPase at the basolateral membrane