- Total body water content averages 50-60% in healthy adults
“60% of total body water is intracellular and 40% is extracellular”
Sodium Balance – Addition of Solute
Sodium Balance – Addition of Water
Kidney Sodium Handling
- Average diet contains ~900 mOsm/day
- Urine can be maximally diluted to ~50 mOsm/L and maximally concentrated to ~1200 mOsm/L
- Urine output from a healthy kidney can vary from 0.75 – 18 L/day (900/1200 – 900/50)
- Concentration largely governed by vasopressin
“Kidney tries to maintain normal plasma osmolarity”
