Normal urine is clear, transparent and has no sediments. Its color is light pale like straw because of the presence of urobilin pigment but it keeps on changing according to the quantity of pigment. It has a special kind of aromatic odour too. A change can come in the odour of the urine because of gathering urine and the presence of abnormal elements.
The pH of normal urine is between 5.0 and 8.0 but it is little acidic. Its pH changes according to the meal taken by a person. The pH of those people who eat meat daily is between 5 and 6 and the pH of vegetarian people is between 7 and 8.
Specific gravity of urine is equal to the thickness of the urine which is generally between 1.012 and 1.024.
Composition of Urine:
The components of the urine and their thickness keep on changing according to the meal, water taken by a person, exercise and other factors. Generally, the water is the main component of urine which is about 90 percent and solid substances are 5 percent which are soluble in the water. There are two percent urea (amino acid is the water product of metabolism) in five percent solid substances and there are 3 percent carbonic substances (uric acid, keatin, ammonia, acetone bodies and inorganic substance (sodium chloride, potassium, sulphte, phosphate, calcium and other substances.)
- Protein (albumin)-in the condition of diseases
- glucose- in diabetes
- acetone-fast in diabetes
- bile-in jaundice disease
- castus (decomposed blood cells, renal cells) and crystal (particles of stone)
Volume of Urine:
Excretion of 450 ml urine from the body in a day is very necessary to sustain the osmotic concentration of external cells liquid (with blood), to expel out waste substances from the body and to sustain the activity of kidneys. Generally, a healthy person excretes 1000 to 1800 ml urine in a day on the normal activity and drinking water.
The quantity of excreted urine can be affected by the water intake, meal, atmosphere temperature, hormonal and enzymatic activities, blood pressure, diuretics and emotional states. The quantity of urine gets reduced in excessive perspiration, loose motions or vomiting and hard labor.
The volume and concentration of urine is governed by the antidiuretic hormone (ADH), aldosterone hormone and by the enzyme named rennin. The ADH excreted by the pituitary gland controls the permeability of walls of collecting ducts. The ADH is excreted on large scale in the condition of dehydration and because of this reason the person passes urine in little quantity. The ADH is excreted in a little quantity in the overhydration condition of the body and the person passes urine on large scale. Aldosterone hormone that is excreted by the cortex of adrenal gland increases the reabsorption of sodium from the kidneys because of which the quantity of sodium gets reduced in the urine.
There is an augmentation in the rate of glomerular filtration because of increasing blood pressure in the renal circulation and the volume of urine gets increased. Just opposite of it, there is an obstruction in the activity of filtration when the blood pressure gets reduced and the volume of urine gets reduced.
The water is not filtered when the osmotic pressure is high in the fluid of renal cells and consequently the quantity of urine gets reduced.
The volume of the excreted urine depends on the number of active glomeruli and their working capacity, glomeruli filtrate membrane and on the condition of renal tubes.
Some special stimulated foodstuffs as mustard, chilly, tea, coffee, alcohol and vitamin C in excessive quantity increases the production of urine. On the contrary, the nicotine reduces the production of urine. The production of urine gets reduced at night and this is the reason that we don’t get disturbed at night.