Contents of urine include water, salts, electrolytes such as potassium and phosphorous, chemicals like urea and uric acid. Urine also contains pigmented products of blood broken-down, one of them being urochrome, due to which urine is yellow in colour.
In humans, and most mammals, urine is formed with the blood enters the nephrons of the kidney. Water and useful products like glucose, amino acids, sodium and other nutrients are reabsorbed into the bloodstream, with the waste material retained inside nephrons to be processed as urine. Any unusual substances that does not have a mechanism of reabsorption is also discarded as urine. Here are some facts about urine.
- A normal adult secretes about 1.4 liters of urine per day, emptying
- Urine concentration depends upon various factors like:
- Level of physical work
- Environment – humidity and temperature
- Level of water intake
- Levels of intake of salt and protein
- Other dissolved ions
- Organic and inorganic compounds.
The normal solute concentrations of urine are as given below.
- Urea – 9.3 g/dL
- Creatinine – 0.670 g/dL
- Sodium – 1.17 g/L
- Potassium – 0.750 g/L
- Chloride – 1.87 g/L
Testing of urine:
- Red blood cells
- White blood cells
Microscopic examination of urine reveals the number and type of cells, casts, crystals, bacteria and mucus.
Urine plays an important role in maintaining the water content and the toxins of the body. It is also an important component that indicates the health of the individual.