Sodium Na | (24 hour urine)

General Information

Sodium Excreted from the body mainly by the kidneys. Renal excretion of Na + is affected by glomerular filtration rate, changes in serum Na + concentration, adrenal cortex activity, amount of non-absorbable substances in the filtrate, and volume of extracellular fluid. Each of these five parameters acts differently on the amount of Na + filtered or reabsorbed. The amount of Na + that occurs in the urine is the difference between the amount filtered by the glomerulus and the amount reabsorbed in the tubular lumen. Urinary excretion of Na + is usually only 1% of the filtered amount.