Piss
Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream. The resulting urine contains high concentrations of urea and other substances, including toxins.
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Urine is an aqueous solution of greater than 95% water, with the remaining constituents, in order of decreasing concentration urea 9.3 g/L, chloride 1.87 g/L, sodium 1.17 g/L, potassium 0.750 g/L, creatinine 0.670 g/L and other dissolved ions, inorganic and organic compounds.
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Urine is sterile until it reaches the urethra where the epithelial cells lining the urethra are colonized by facultatively anaerobic Gram negative rods and cocci.[4] Subsequent to elimination from the body, urine can acquire strong odors due to bacterial action,[citation needed] and in particular the release of asphyxiating ammonia from the breakdown of urea. In medieval times clothes were stored in a garderobe (literally ‘to guard ones robes’) close to the toilet shaft because this ammonia would kill the fleas.[5] The term garderobe became a euphemism for toilet for that reason.
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Ancient Romans used human urine to cleanse grease stains from their clothing, before acquiring soaps from the Germans during the first century AD.[39] Urine that has been fermented for the purposes of cleaning is referred to as lant. The emperor Nero instituted a tax (Latin: vectigal urinae) on the urine industry. This tax was continued by Nero’s successor, Vespasian. Vespasian’s name is still attached to public urinals in France (vespasiennes), Italy (vespasiani), and Romania (vespasiene).
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The word “urine” was first used in the 14th century. Before that, the concept was described by the now vulgar word “piss”. Onomatopoetic in origins, “piss” was the primary means of describing urination, as “urinate” was at first used mostly in medical contexts.
(http://en.wikipedia.org/wiki/Urine#cite_ref-38)
Brain centers that regulate urination include the pontine micturition center, periaqueductal gray, and the cerebral cortex.
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During storage, bladder pressure stays low, because of the bladder’s highly compliant nature. A plot of bladder (intravesical) pressure against the depressant of fluid in the bladder (called a cystometrogram) will show a very slight rise as the bladder is filled. This phenomenon is a manifestation of the law of Laplace, which states that the pressure in a spherical viscus is equal to twice the wall tension divided by the radius.
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Diuresis (production of urine by the kidney) occurs constantly, and as the bladder becomes full, afferent firing increases, yet the micturition reflex can be voluntarily inhibited until it is appropriate to begin voiding.
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Post-micturition convulsion syndrome, the feeling of a shiver running down the spine following urination, occurs in most males and many females.
(http://en.wikipedia.org/wiki/Micturition)
Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. It is solid, colourless, and odorless (although the ammonia that it gives off in the presence of water, including water vapor in the air, has a strong odor)…The body uses it in many processes, the most notable one being nitrogen excretion. Urea is widely used in fertilizers as a convenient source of nitrogen…The synthesis of this organic compound by Friedrich Wöhler in 1828 from an inorganic precursor was an important milestone in the development of organic chemistry, as it showed for the first time that a molecule found in living organisms could be synthesized in the lab without biological starting materials (thus contradicting a theory widely prevalent at one time, called vitalism).
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In aquatic organisms the most common form of nitrogen waste is ammonia, whereas land-dwelling organisms convert the toxic ammonia to either urea or uric acid. Urea is found in the urine of mammals and amphibians, as well as some fish. Birds and saurian reptiles have a different form of nitrogen metabolism, that requires less water and leads to nitrogen excretion in the form of uric acid. It is noteworthy that tadpoles excrete ammonia but shift to urea production during metamorphosis.
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Urea absorbs moisture from the atmosphere and therefore is typically stored either in closed/sealed bags on pallets or, if stored in bulk, under cover with a tarpaulin.
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Urea-containing creams are used as topical dermatological products to promote rehydration of the skin.
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Like saline, urea injection is used to perform abortions.
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By virtue of its tendency to form a porous frameworks, urea has the ability to trap many organic compounds.
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Many animals (e.g., dogs) have a much more concentrated urine and it contains a higher urea amount than normal human urine; this can prove dangerous as a source of liquids for consumption in a life-threatening situation (such as in a desert).
Urea can cause algal blooms to produce toxins, and its presence in the runoff from fertilized land may play a role in the increase of toxic blooms.[18]
(http://en.wikipedia.org/wiki/Urea)
Around 1669 he (Hennig Brand) heated residues from boiled-down urine on his furnace until the retort was red hot, where all of a sudden glowing fumes filled it and liquid dripped out, bursting into flames. He could catch the liquid in a jar and cover it, where it solidified and continued to give off a pale-green glow. What he collected was phosphorus, which he named from the Greek word for “light-bearing” or “light-bearer.”
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He used about 5,500 litres of urine to produce just 120 grams of phosphorus. If he had ground up the entire residue he could have got 10 times or 100 times more (1 litre of adult human urine contains about 1.4g phosphorus).
