Control of sodium excretion
Decide whether the following statements are true or false.
| In a normal adult, approximately 27000 mmol of sodium is filtered each day. |
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| As GFR falls, there becomes an imbalance between intake and excretion of sodium. |
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| The main driving force for reabsorption of sodium is the low sodium concentration in the ICF. |
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| Sodium moves via co-transporters involving glucose and amino acids. |
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As well as these cotransporters, there is also a Na+-H+ exchanger (NHE-3), whose main role is in the reabsorption of NaHCO3.
When the ECF volume is contracted, there will be virtually no sodium in the urine, while if there is ECF volume expansion, sodium will be excreted. In a euvolaemic state, sodium excretion will equal dietary intake.