What is Urine?
Urine is the fluid secreted from the blood by the kidneys, stored in the bladder and discharged by the urethra. In healthy humans, it is amber colored. About 1,250 milliliters (about a third of a gallon or 0.044 cu ft of urine are excreted in 24 hours with normal specific gravities of 1,024. Flow ranges from 0.5 to 20 milliliters/minute with extremes of dehydration and hydration.
Composition of Urine Normally Produced Daily by an Adult
Substance | Amount |
Urea | 6.0 – 180 grams (nitrogen) |
Creatine | 0.3 – 0.8 gram (nitrogen) |
Ammonia | 0.4 – 1.0 gram (nitrogen) |
Uric acid | 0.008 – 0.2 gram (nitrogen) |
Sodium | 2.0 – 4.0 grams |
Potassium | 1.5 – 2.0 grams |
Calcium | 0.1 – 0.3 gram |
Magnesium | 0.1 – 0.2 gram |
Chloride | 4.0 – 8.0 grams |
Phosphate | 0.7 – 1.6 gram (phosphorus) |
Inorganic sulfate | 0.6 – 1.8 gram (sulfur) |
Organic sulfate | 0.006 – 0.2 gram (sulfur) |
Source: Van Nostrand’s Scientific Encyclopedia