urine(redirected from block urine)
Also found in: Dictionary, Thesaurus, Medical.
An aqueous solution of organic and inorganic substances, mostly waste products of metabolism. The kidneys maintain the internal milieu of the body by excreting these waste products and adjusting the loss of water and electrolytes to keep the body fluids relatively constant in amount and composition. The urine normally is clear and has a specific gravity of 1.017–1.020, depending upon the amount of fluid ingested, perspiration, and diet. The increase in specific gravity above that of water is due to the presence of dissolved solids, about 60% of which are organic substances such as urea, uric acid, creatinine, and ammonia; and 40% of which are inorganic substances such as sodium, chloride, calcium, potassium, phosphates, and sulfates. Its reaction is usually acid (pH 6) but this too varies with the diet. It usually has a faint yellow color due to a urochrome pigment, but the color varies depending upon the degree of concentration, and the ingestion of certain foods (for example, rhubarb) or cathartics. It usually has a characteristic aromatic odor, the cause of which is not known. See Kidney, Urea, Uric acid, Urinary system
a human and animal excretion that is produced by the kidneys. Water, salts, end products of metabolism, and foreign substances are excreted with the urine. Human urine is normally a transparent, yellow fluid; the color is dependent on the presence of several pigments, chiefly the products of the decomposition of hemoglobin. The specific gravity of urine is 1.010–1.025 g/cm3, and the pH ranges from 4.8 to 8.0. Intake of protein-rich foods results in acidic urine, while consumption of vegetables causes the urine to be weakly alkaline. About 96 percent of urine consists of water; 1.5 percent, of salts; and 2.5 percent, of such organic metabolic products as urea and uric acid. Urine and blood plasma contain the same salts—mainly NaCl, and also sulfates, phosphates, and carbonates of potassium, magnesium, and ammonium.
An adult excretes 1,200–1,600 ml of urine daily. The volume and composition of the urine are dependent on several factors, including the nature of an individual’s liquid intake, the type of food eaten, the temperature of the external environment, and stress factors. Urinalysis is a diagnostic method that reflects the condition of the kidneys, of the metabolism in other organs and tissues, and of the body as a whole.
REFERENCEGulevich, V. S. Analiz mochi. Leningrad, 1945.
M. IA. RATNER