Urine

Most animals have excretory systems for elimination of soluble toxic wastes. In humans, soluble wastes are excreted primarily by the urinary system and, to a lesser extent in terms of urea, removed by perspiration. In placental mammals, the urinary system consists of the kidneys, ureters, urinary bladder, and urethra. The system produces urine by a process of filtration, reabsorption, and tubular secretion. The kidneys extract the soluble wastes from the bloodstream, as well as excess water, sugars, and a variety of other compounds. The resulting urine contains high concentrations of urea and other substances, including toxins. Urine flows from the kidneys through the ureter, bladder, and finally the urethra before passing through the urinary meatus. Duration Research looking at the duration of urination in a range of mammal species found that nine larger species urinated for 21 ± 13 seconds irrespective of body size. Smaller species, including rodents and bats, cannot produce steady streams of urine and instead urinate with a series of drops. ==Characteristics==

Quantity The adult human bladder typically holds between 300 and (10 and ) of urine before urination, but it can hold considerably more. Average urine production in adult humans is around of urine per person per day with a normal range of per person per day, produced in around 6 to 8 urinations per day depending on state of hydration, activity level, environmental factors, weight, and the individual's health. Producing too much or too little urine needs medical attention. Polyuria is a condition of excessive production of urine (> 2.5 L/day), oliguria when The pH normally is within the range of 5.5 to 7 with an average of 6.2. Urine pH can be monitored by a physician or at home. A diet which is high in protein from meat and dairy, as well as alcohol consumption can reduce urine pH, whilst potassium and organic acids, such as from diets high in fruit and vegetables, can increase the pH and make it more alkaline. Drugs that can decrease urine pH include ammonium chloride, chlorothiazide diuretics, and methenamine mandelate. Density Human urine has a specific gravity of 1.003–1.035. contrary to longstanding popular belief. This opened a new area of study: the urinary microbiome. In the urethra, epithelial cells lining the urethra are colonized by facultatively anaerobic Gram-negative rod and cocci bacteria. One study conducted in Nigeria isolated a total of 77 distinct bacterial strains from 100 healthy children (ages 5–11) as well as 39 strains from 33 cow urine samples, a considerable amount being pathogens. Pathogens identified and their percentages were: The study also states: ==Examination for medical purposes==

. Many physicians in ancient history resorted to the inspection and examination of the urine of their patients. Hermogenes wrote about the color and other attributes of urine as indicators of certain diseases. Abdul Malik Ibn Habib of Andalusia ( 862 AD) mentions numerous reports of urine examination throughout the Umayyad empire. Diabetes mellitus got its name because the urine is plentiful and sweet. The name uroscopy refers to any visual examination of the urine, including microscopy, although it often refers to the aforementioned prescientific or Proto-scientific forms of urine examination. Clinical urine tests today duly note the color, turbidity, and odor of urine but also include urinalysis, which chemically analyzes the urine and quantifies its constituents. A culture of the urine is performed when a urinary tract infection is suspected, as bacteriuria without symptoms does not require treatment. A microscopic examination of the urine may be helpful to identify organic or inorganic substrates and help in the diagnosis. The color and volume of urine can be reliable indicators of hydration level. Clear and copious urine is generally a sign of adequate hydration. Dark urine is a sign of dehydration. The exception occurs when diuretics are consumed, in which case urine can be clear and copious and the person still be dehydrated. == Uses ==

from it (Ede, the Netherlands) Source of medications Urine contains proteins and other substances that are useful for medical therapy and are ingredients in many prescription drugs. Urine from postmenopausal women is rich in gonadotropins that can yield follicle stimulating hormone and luteinizing hormone for fertility therapy. One such commercial product is Pergonal. Urine from pregnant women contains enough human chorionic gonadotropins for commercial extraction and purification to produce hCG medication. Pregnant mare urine is the source of estrogens, namely Premarin. Urine can also be used to produce urokinase, which is used clinically as a thrombolytic agent. Fertilizer Cleaning Given that urea in urine breaks down into ammonia, urine has been used for cleaning. In pre-industrial times, urine was used – in the form of lant or aged urine – as a cleaning fluid. Urine was also used for whitening teeth in Ancient Rome. Gunpowder Urine was used before the development of a chemical industry in the manufacture of gunpowder. Urine, a nitrogen source, was used to moisten straw or other organic material, which was kept moist and allowed to rot for several months to over a year. The resulting salts were washed from the heap with water, which was evaporated to allow collection of crude saltpeter crystals, that were usually refined before being used in making gunpowder. Survival uses Urophagia is the consumption of urine. Urine was consumed in several ancient cultures for various health, healing, and cosmetic purposes. People have been known to drink urine in extreme cases of water scarcity. The US Army Field Manual advises drinking urine for survival. The manual explains that drinking urine tends to worsen rather than relieve dehydration due to the salts in it, and that urine should not be consumed in a survival situation, even when there is no other fluid available. In hot weather survival situations, where other sources of water are not available, soaking cloth (a shirt for example) in urine and putting it on the head can help cool the body. During World War I, Germans experimented with numerous poisonous gases as weapons. After the first German chlorine gas attacks, Allied troops were supplied with masks of cotton pads that had been soaked in urine. It was believed that the ammonia in the pad neutralized the chlorine. These pads were held over the face until the soldiers could escape from the poisonous fumes. Urban legend states that urine works well against jellyfish stings. This scenario has appeared many times in popular culture including in the Friends episode "The One With the Jellyfish", an early episode of Survivor, as well as the films The Real Cancun (2003), The Heartbreak Kid (2007) and The Paperboy (2012). However, at best it is ineffective, and in some cases this treatment may make the injury worse. Textiles Urine has often been used as a mordant to help prepare textiles, especially wool, for dyeing. In the Scottish Highlands and Hebrides, the process of "waulking" (fulling) woven wool is preceded by soaking in urine, preferably infantile. Olfactory communication Urine plays a role in olfactory communication, since it contains semiochemicals that act as pheromones. The urine of predator species often contains kairomones that serve as a repellent against their prey species. ==History==

text from the Red Book of Hergest on uroscopy, called (the 'Qualities of Urine'). Opening lines (translated): "Since it is through the qualities of the urine that a person's faults and his dangers and his diseases and his illness can be identified..." The fermentation of urine by bacteria produces a solution of ammonia; hence fermented urine was used in Classical Antiquity to wash cloth and clothing, to remove hair from hides in preparation for tanning, to serve as a mordant in dying cloth, and to remove rust from iron. Ancient Romans used fermented human urine (in the form of lant) to cleanse grease stains from clothing. The emperor Nero instituted a tax () on the urine industry, continued by his successor, Vespasian. The Latin saying ('money does not smell') is attributed to Vespasian – said to have been his reply to a complaint from his son about the unpleasant nature of the tax. Vespasian's name is still attached to public urinals in France (), Italy (), and Romania (). Alchemists spent much time trying to extract gold from urine, which led to discoveries such as white phosphorus by German alchemist Hennig Brand when distilling fermented urine in 1669. In 1773 the French chemist Hilaire Rouelle discovered the organic compound urea by boiling urine dry. == Language ==

The English word urine (, ) comes from the Latin (-ae, f.), which is cognate with ancient words in various Indo-European languages that concern water, liquid, diving, rain, and urination (for example Sanskrit meaning 'it rains' or meaning 'water' and Greek meaning 'to urinate'). The onomatopoetic term piss predates the word urine, but is now considered vulgar. Urinate was at first used mostly in medical contexts. Piss is also used in such colloquialisms as to piss off, piss poor, and the slang expression pissing down to mean heavy rain. Euphemisms and expressions used between parents and children (such as wee, pee, number one and many others) have long existed. Lant is a word for aged urine, originating from the Old English word referring to urine in general. ==See also==