Urination, also known as micturition, voiding, and, more rarely, emiction, is the process of disposing urine from the urinary bladder through the urethra to the outside of the body. Urine is a liquid waste product of the body secreted by the Kidneys by a process of filtration from Blood and Excreted through the Urethra. In Anatomy, the urinary bladder is a hollow muscular, and distensible (or elastic organ that sits on the Pelvic floor in Mammals It is the In Anatomy, the urethra (from Greek ουρήθρα - ourethra) is a tube which connects the Urinary bladder to the outside of In healthy adults, the process of urination is under voluntary control; in infants and individuals with neurological injury, urination may occur as an involuntary reflex.
Contents |
Urination is often referred to as "peeing", a euphemism for "piss" which is considered more vulgar. It is also referred to as "weeing" or "doing/having a wee-wee", though not in North America.
"To whiz" or "whizzing" is common in the U. S. "To piddle" is common in the U. K. , as well as "to have a slash", which originates from the Scottish word "slash" meaning a large splash of liquid. [1] Others of note are "tinkle" and "potty" - both of which are often used with children. Tinkle is an Indian monthly comic Indian magazine published in several Indian languages.
The main organs involved in urination are the bladder and the urethra. In Anatomy, the urinary bladder is a hollow muscular, and distensible (or elastic organ that sits on the Pelvic floor in Mammals It is the In Anatomy, the urethra (from Greek ουρήθρα - ourethra) is a tube which connects the Urinary bladder to the outside of The smooth muscle of the bladder, known as the detrusor, is innervated by sympathetic nervous system fibers from the lumbar spinal cord and parasympathetic fibers from the sacral spinal cord. In Anatomy, the urinary bladder is a hollow muscular, and distensible (or elastic organ that sits on the Pelvic floor in Mammals It is the In Anatomy, lumbar is an Adjective that means of or pertaining to the Abdominal segment of the Torso, between the diaphragm and The parasympathetic Nervous system ( PSNS) is a division of the Autonomic nervous system (ANS along with the Sympathetic nervous system [2] Fibers in the pelvic nerves constitute the main afferent limb of the voiding reflex; the parasympathetic fibers to the bladder that constitute the excitatory efferent limb also travel in these nerves. Part of the urethra is surrounded by the external urinary sphincter, which is innervated by somatic fibers originating in the sacral cord, in an area termed Onuf's nucleus[3].
Muscle bundles pass on either side of the urethra, and these fibers are sometimes called the internal urethral sphincter, although they do not encircle the urethra. Farther along the urethra is a sphincter of skeletal muscle, the sphincter of the membranous urethra (external urethral sphincter). The bladder's epithelium is termed transitional epithelium which contains a superficial layer of dome-like cells and multiple layers of stratified cuboidal cells underneath when evacuated. Transitional epithelium (also known as urothelium is a type of tissue consisting of multiple layers of Epithelial cells which can contract and expand When the bladder is fully distended the superficial cells become squamous (flat) and the stratification of the cuboidal is reduced in order to provide lateral stretching.
The physiology of micturition and the physiologic basis of its disorders are subjects about which there is much confusion, especially at the supraspinal level. Micturition is fundamentally a spinobulbospinal reflex facilitated and inhibited by higher brain centers and, like defecation, subject to voluntary facilitation and inhibition. Defecation is the final act of Digestion by which organisms eliminate solid semisolid or liquid Waste material ( Faeces) from the Digestive tract [4]
In healthy individuals, the lower urinary tract has two discrete phases of activity: the storage phase, when urine is stored in the bladder; and the voiding phase, when urine is released through the urethra. The state of the reflex system is dependent on both a conscious signal from the brain and the firing rate of sensory fibers from the bladder and urethra. [4] At low bladder volumes, afferent firing is low, resulting in excitation of the outlet (the sphincter and urethra), and relaxation of the bladder. [5] At high bladder volumes, afferent firing increases, causing a conscious sensation of urinary urge. When the individual is ready to urinate, he or she consciously initiates voiding, causing the bladder to contract and the outlet to relax. Voiding continues until the bladder empties completely, at which point the bladder relaxes and the outlet contracts to re-initiate storage. [4] The muscles controlling micturition are controlled by the autonomic and somatic nervous systems. &trade The autonomic nervous system ( ANS) (or visceral nervous system) is the part of the Peripheral nervous system that acts as a Control During the storage phase the internal urethral sphincter remains tense and the detrusor muscle relaxed by sympathetic stimulation. The Sympathetic Nervous System ( SNS) is a branch of the Autonomic nervous system along with the Enteric nervous system and Parasympathetic nervous During micturition, parasympathetic stimulation causes the detrusor muscle to contract and the internal urethral sphincter to relax. The parasympathetic Nervous system ( PSNS) is a division of the Autonomic nervous system (ANS along with the Sympathetic nervous system The external urethral sphincter (sphincter urethrae) is under somatic control and is consciously relaxed during micturition.
In infants, voiding occurs involuntarily (as a reflex). The ability to voluntarily inhibit micturition develops at the age of 2-3 years, as control at higher levels of the central nervous system develops. In the adult, the volume of urine in the bladder that normally initiates a reflex contraction is about 300-400 mL.
During storage, bladder pressure stays low, because of the bladder's highly compliant nature. A plot of bladder (intravesical) pressure against the volume 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. In the case of the bladder, the tension increases as the organ fills, but so does the radius. Therefore, the pressure increase is slight until the organ is relatively full. The bladder smooth muscle has some inherent contractile activity; however, when its nerve supply is intact, stretch receptors in the bladder wall initiate a reflex contraction that has a lower threshold than the inherent contractile response of the muscle.
Action potentials carried by sensory neurons from stretch receptors in the urinary bladder wall travel to the sacral segments of the spinal cord through the pelvic nerves. [4] Since bladder wall stretch is low during the storage phase, these afferent neurons fire at low frequencies. Low-frequency afferent signals cause relaxation of the bladder by inhibiting sacral preganglionic neurons and exciting lumbar sympathetic preganglionic neurons. Conversely, afferent input causes contraction of the sphincter through excitation of Onuf's nucleus, and contraction of the bladder neck and urethra through excitation of the sympathetic preganglionic neurons.
As the bladder becomes full, afferent firing increases, yet the micturition reflex can be voluntarily inhibited until it is appropriate to begin voiding (e. g. a bathroom is reached).
Voiding begins when a voluntary signal is sent from the brain to begin urination, and continues until the bladder is empty.
Bladder afferent signals ascend the spinal cord to the periaqueductal gray, where they project both to the pontine micturition center and to the cerebrum [6]. At a certain level of afferent activity, the conscious urge to void becomes difficult to ignore. Once the voluntary signal to begin voiding has been issued, neurons in pontine micturition center fire maximally, causing excitation of sacral preganglionic neurons. The firing of these neurons causes the wall of the bladder to contract; as a result, a sudden, sharp rise in pressure in intravesical pressure occurs. The pontine micturition center also causes inhibition of Onuf's nucleus, resulting in relaxation of the external urinary sphincter. [7] When the external urinary sphincter is relaxed urine flows from the urinary bladder when the pressure there is great enough to force urine to flow through the urethra. The micturition reflex normally produces a series of contractions of the urinary bladder.
The flow of urine through the urethra has an overall excitatory role in micturition, which helps sustain voiding until the bladder is empty. [8]
After urination, the female urethra empties by gravity. Urine remaining in the urethra of the male is expelled by several contractions of the bulbospongiosus muscle. Bulbospongiosus ( bulbocavernous in older texts is one of the superficial Muscles of the Perineum.
The mechanism by which voluntary urination is initiated remains unsettled. [9] One possibility is that the voluntary relaxation of the muscles of the pelvic floor causes a sufficient downward tug on the detrusor muscle to initiate its contraction. When Urinating, it contracts to squeeze out urine Otherwise it remains relaxed to allow the bladder to fill [10] Another possibility is the excitation or disinhibition of neurons in the pontine micturition center, which causes concurrent contraction of the bladder and relaxation of the sphincter. [4]
There is an inhibitory area for micturition in the midbrain. After transection of the brain stem just above the pons, the threshold is lowered and less bladder filling is required to trigger it, whereas after transection at the top of the midbrain, the threshold for the reflex is essentially normal. There is another facilitatory area in the posterior hypothalamus. In humans with lesions in the superior frontal gyrus, the desire to urinate is reduced and there is also difficulty in stopping micturition once it has commenced. However, stimulation experiments in animals indicate that other cortical areas also affect the process.
The bladder can be made to contract by voluntary facilitation of the spinal voiding reflex when it contains only a few milliliters of urine. Voluntary contraction of the abdominal muscles aids the expulsion of urine by increasing the pressure applied to the urinary bladder wall, but voiding can be initiated without straining even when the bladder is nearly empty. The human abdomen (from the Latin word meaning "belly" is the part of the body between the Pelvis and the thorax.
Voiding can also be consciously interrupted once it has begun, through a contraction of the perineal muscles and the external sphincter can be contracted voluntarily, which will prevent urine from passing down the urethra.
Need to urinate is experienced as an uncomfortable, full, feeling. It is highly correlated with the fullness of the bladder. [11] In males the feeling of the need to urinate can be sensed at the base of the penis, even though the neural activity associated with a full bladder comes from the bladder itself. In females the need to urinate is felt in the lower abdomen in the region of the bladder.
Release of urine is experienced as a lessening of the uncomfortable, full, feeling. In most people it is a relief if their bladder is full.
Post-micturition convulsion syndrome, the feeling of a shiver running down the spine following urination, occurs in more than 80% of males, but also occurs in more than 55% of females[12]. Post-micturition convulsion syndrome, also colloquially known as piss shivers or pee shivers is a phenomenon in which one feels a Shiver running down the Its explanation is unknown.
There are three major types of bladder dysfunction due to neural lesions: (1) the type due to interruption of the afferent nerves from the bladder; (2) the type due to interruption of both afferent and efferent nerves; and (3) the type due to interruption of facilitatory and inhibitory pathways descending from the brain. Constantine the African ( Latin Constantinus Africanus c 1020 Carthage or Sicily&ndash1087 monastery of Monte Cassino, near Cassino Principality In all three types the bladder contracts, but the contractions are generally not sufficient to empty the viscus completely, and residual urine is left in the bladder. Paruresis, also known as shy bladder syndrome, is an example of a bladder interruption from the brain that often causes total interruption until the person has left a public area. Paruresis (pærjəˈriːsɪs also known as pee shyness, shy kidney, bashful bladder, stage fright, urophobia or shy bladder
When the sacral dorsal roots are cut in experimental animals or interrupted by diseases of the dorsal roots such as tabes dorsalis in humans, all reflex contractions of the bladder are abolished. The bladder becomes distended, thin-walled, and hypotonic, but there are some contractions because of the intrinsic response of the smooth muscle to stretch.
When the afferent and efferent nerves are both destroyed, as they may be by tumors of the cauda equina or filum terminale, the bladder is flaccid and distended for a while. Gradually, however, the muscle of the "decentralized bladder" becomes active, with many contraction waves that expel dribbles of urine out of the urethra. The bladder becomes shrunken and the bladder wall hypertrophied. The reason for the difference between the small, hypertrophic bladder seen in this condition and the distended, hypotonic bladder seen when only the afferent nerves are interrupted is not known. The hyperactive state in the former condition suggests the development of denervation hypersensitization even though the neurons interrupted are preganglionic rather than postganglionic.
During spinal shock, the bladder is flaccid and unresponsive. It becomes overfilled, and urine dribbles through the sphincters (overflow incontinence). After spinal shock has passed, the voiding reflex returns, although there is, of course, no voluntary control and no inhibition or facilitation from higher centers when the spinal cord is transected. Some paraplegic patients train themselves to initiate voiding by pinching or stroking their thighs, provoking a mild mass reflex. In some instances, the voiding reflex becomes hyperactive. Bladder capacity is reduced, and the wall becomes hypertrophied. This type of bladder is sometimes called the spastic neurogenic bladder. The reflex hyperactivity is made worse by, and may be caused by, infection in the bladder wall.
Many clinical conditions can cause disturbances to normal urination. Here is a partial list:
Due to the differences in where the urethra ends, males and females use different techniques for urination. In Anatomy, the urethra (from Greek ουρήθρα - ourethra) is a tube which connects the Urinary bladder to the outside of
Because of the flexible and protruding nature of the penis, it is simple to control the direction of the urine stream. The penis (plural penises, penes This makes it easy to urinate while standing; many males urinate this way. Standing is a Human position in which the body is constantly in an orthostatic state Extant foreskin (acropostheon) may block the direct path of the outgoing stream by causing turbulence, resulting in a slower but thicker stream of urine that may also dribble. In Fluid dynamics, turbulence or turbulent flow is a fluid regime characterized by chaotic Stochastic property changes A retracted or absent foreskin may have a more focused stream of urine that travels at the same speed it exits the urethra. In Anatomy, the urethra (from Greek ουρήθρα - ourethra) is a tube which connects the Urinary bladder to the outside of When a male is done urinating, he will usually shake and/or gently squeeze his penis to expel the excess urine trapped in the opening of the foreskin or on the glans. The glans penis (or simply glans) is the sensitive tip of the Penis. Trousers usually have a fly allowing men to urinate without lowering the whole trousers: The fly has buttons or a zipper. Trousers are an item of Clothing worn on the lower part of the body from the waist to the ankles covering both legs separately (rather than with cloth stretching across In Clothing and Fashion design, a button is a small plastic or metal disc- or knob-shaped typically round object usually attached to an article of Clothing zipper (data structure A zipper ( English: zip fastener or zip) is a popular device for temporarily joining two edges of fabric. Either just the fly is opened or also the fastening at the waist. If underpants are worn, the fly of the underpants is used or their front-side is lowered. All combinations are possible. Trousers without a fly, like some jogging trousers, usually have an elastic waist band allowing lowering the front side like underpants. When out in public a man will sometimes pee into a urinal, while at home he will usually urinate into a toilet bowl. (Urinals are uncommon in private dwellings, although their lack of standing water is environmentally beneficial and makes urination into them quiet. )
In females, the urethra opens straight into the vulva. The vulva (from Latin, vulva, plural vulvae or vulvas; see etymology) is the region of the external genital organs Because of this, the urine does not exit at a distance from her body and is therefore very hard to control. Because of surface tension in the urine, the easiest method is to rely simply on gravitational force to take over once the urine has exited her body. For the work of fiction see Surface Tension (short story. Surface tension is a property of the surface of a Liquid that causes it to Gravitation is a natural Phenomenon by which objects with Mass attract one another This can easily be achieved if the female is sitting on a toilet. When sitting, it helps if the female leans forward and keeps her legs together, as this helps direct her stream downwards. When not urinating into a toilet, squatting is the easiest way for a female to direct her urine stream. Some females use one or both hands to focus the direction of the urine stream, which is more easily achieved while in the squatting position.
Some females prefer to not sit all the way down on a toilet seat, to avoid contact with the toilet. This technique is known as hovering or squatting. These alternative choices are sometimes made because of perceived or actual unsanitary conditions. Sanitation is the hygienic means of preventing human contact from the hazards of wastes to promote health However, the resultant loss of accuracy often increases the presence of urine on the toilet seat and leads to a positive feedback loop. Positive feedback, sometimes referred to as "cumulative causation" is a Feedback loop system in which the system responds to perturbation in the same direction This approach could even be considered an example of the tragedy of the commons. The Tragedy of the Commons is the title of an influential article written by Garrett Hardin, first published in the journal Science in 1968.
Women who wear pants, trousers, or shorts will need to lower these garments to urinate. Women wearing skirts or dresses only need to raise them to their waists to urinate, just lowering the underpants. While urinating in the squatting position, pants are often just lowered to the midst of the thighs, and some women lift the midst of the lowered underpants up. Some women hold the front of their underpants or bikinipants to the side, hence not having to pull them down.
It is possible for many females to urinate standing while spreading their legs. This technique for urinating while standing can be common when females often wear a sarong, skirt, or other such open bottomed garments, and either wear no underwear, or remove it. A sarong or sarung (ˈsaɾoŋ in Malay, and səˈrɒŋ in English) is a large sheet of fabric, often wrapped around the waist and worn as A skirt is a tube- or cone-shaped Garment that hangs from the Waist and covers all or part of the Legs In European culture, skirts are usually Undergarments are clothes worn under other clothes often next to the skin It is considered normal for females to urinate like this in many parts of Africa, whereas in contrast, it is not completely accepted in countries such as India where it also occurs in some areas. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country In Africa, even signs which forbid public urination often show a picture of a female urinating while standing. A sign is an entity which signifies another entity A natural sign is an entity which bears a causal relation to the signified entity as thunder is a sign of storm [13]. It is mostly in West Africa, like Ghana and Nigeria, that it is considered normal for a female to urinate standing up. In many other parts it mostly occurs in the countryside or not at all.
Though uncommon, it is possible for females to urinate standing up in a way similar to that of males. This may be done by spreading the labia minora open in a certain way and orienting the pelvis at an angle and rapidly forcing the urine stream out. The pelvis (pl pelvises or pelves) or pelvic girdle is the irregular bony structure located at the base of the spine (properly known [14] An alternative method is to use a tool known as a female urination device to assist. A female urination device (FUD or female urination aid is a small funnel which enables a woman to urinate while standing upright The woman's bladder is smaller than the man's.
Occasionally, if a male's penis is damaged or removed, or a female's genitals/urinary tract is damaged, other urination techniques must be used. Most often in such cases, doctors will reposition the urethra to a location where urination can still be accomplished, usually in a position that would only promote urination while seated/squatting, though a permanent urinary catheter may rarely be used in some cases. In urinary catheterization, a plastic tube known as a urinary Catheter (such as a Foley catheter) is inserted into a patient's bladder via their
Babies have no socialized control over urination within societies that do not practice elimination communication and instead use diapers. Elimination communication (EC is a process by which a caregiver uses timing signals cues and intuition to address an infant's excretive needs partially or completely "Nappy" redirects here For other uses see Nappy (disambiguation and Diaper (disambiguation. Toilet training is the process of learning to restrict urination to socially approved times and situations. Toilet training, or potty training, is the process of training a young child to use the Toilet for Urination and Defecation. Many young children suffer from nocturnal enuresis. Bedwetting is involuntary Urination while asleep after the age at which bladder control would normally be anticipated [15]
It is socially more accepted and more hygienic for adults and older children to urinate in a toilet. Philadelphia City Hall is the seat of government for the city of Philadelphia, Pennsylvania. A toilet is a Plumbing fixture and disposal system primarily intended for the disposal of the bodily wastes: Urine and fecal matter. In some countries, public toilets are separated for men and women, and may be partitioned for reasons of cultural modesty. Standards of modesty (also called demureness or reticence) are aspects of the Culture of a Country or people at a given point in time
Public restrooms may have urinals for men. A urinal is a specialized Toilet for urinating only generally by men and boys A urinal is a specialized Toilet for urinating only generally by men and boys Urinals for women, though rare, allow females to urinate while standing through the use of a special tool [16] or through the finger-assist method [17]. Urinals for either sex may have partitions between them in order to increase privacy. Privacy is the ability of an individual or group to seclude themselves or information about themselves and thereby reveal themselves selectively People with a mild form of paruresis, or "shy bladder syndrome," may have difficulty urinating in the presence of others and will consequently avoid using urinals directly adjacent to another person. Paruresis (pærjəˈriːsɪs also known as pee shyness, shy kidney, bashful bladder, stage fright, urophobia or shy bladder Alternatively, they may opt for the privacy of a stall or simply avoid public restrooms altogether.
Acceptability of outdoor urination in a public place other than at a public urinal varies with the situation and with customs. In Architecture, a gargoyle is a carved stone Grotesque with a spout designed to convey water from a roof and away from the side of a building Typically men do this standing up, and women squatting. Potential disadvantages are the "dirtyness", including smell, of urine, and some exposure of genitals. The latter can be unpleasant for the one who exposes them (modesty, lack of privacy) and/or those who can see them; it is avoided or mitigated by going to a quiet place, and/or, for men, facing a tree or wall. Standards of modesty (also called demureness or reticence) are aspects of the Culture of a Country or people at a given point in time Privacy is the ability of an individual or group to seclude themselves or information about themselves and thereby reveal themselves selectively The more developed and crowded a place is the more urination tends to be objectional. In the countryside it is more acceptable than in a street in a town. In the latter case it is a common transgression. Often this is done after the consumption of alcoholic beverages: the alcohol causes production of additional urine as well as a reduction of inhibitions. Social inhibition is what keeps humans from becoming involved in potentially objectionable actions and/or expressions in a social setting In most places, public urination is punishable by fine, though attitudes vary widely by country.
Urination can also be seen and/or intended as a sign of disrespect or contempt for someone or something. In popular culture, signs of a cartoon figure (sometimes Calvin) urinating on another object (usually a car brand) are common. Calvin is a Fictional character in the Comic strip Calvin and Hobbes by Bill Watterson.
Sometimes urination is done in a container such as a bottle, urinal, bedpan or chamber pot, also known as a gazunder, e. A urinal is a specialized Toilet for urinating only generally by men and boys A chamber pot (also a john a chamberpot, a thunder pot, a jordan, a po (from French "pot de chambre") or simply a g. , in case of lying sick in bed, in the case that the urine has to be examined (for medical reasons, or for a drug test), or in the case that there is no toilet or it is inconvenient to go there, and no other possibility to dispose of the urine right away. See also Bedpan use and output measurement. Nursing assistant skills are the set of learned tasks used by nursing assistants in helping residents or patients with Activities of daily living (ADLs and providing
For the latter application a more expensive solution (hence for special occasions while traveling etc. ) is a special disposable bag containing absorbent material that solidifies the urine in 5 to 10 seconds, making it convenient and safe to keep. If used in the presence of others there is still the privacy issue: it is hardly suitable in public transport, because if there is no toilet there is typically no other place to withdraw either; depending on social aspects and/or possibilities to withdraw it may or may not be suitable in a car, boat, private plane, etc. , shared with others. It can also be used for vomiting. Vomiting (also called throwing up, emesis) is the forceful expulsion of the contents of one's Stomach through the Mouth and sometimes the
In many countries and in many social classes even mentioning the need to urinate is seen as a social transgression, although the need is universal. Until recently in the UK many children were taught to say "I need a tidy" or "I need attention" when they needed to be taken to urinate. The abbreviations "tidy" or "tenny" were often used. Other euphemisms, such as 'Spending a penny" (a reference to coin-operated pay toilets); 'Going to see my aunt'; or 'Going to see a man about a dog' were used by adults. A pay toilet is a public toilet that requires Money Payment of any individual to use Even today adults may avoid stating that they need to urinate. In India, especially school students, raise their little finger to indicate the need to pass urine. They may also say they need to go for number "one". This appears to be a universal practice in India.
Urination in art may be controversial. On the other hand, Manneken Pis is famous. Manneken Pis ( Dutch for little man pee) also known in French as the petit Julien, is a very famous Brussels Some pornography depicts urination, see also urolagnia. Pornography or porn is the explicit depiction of Sexual subject matter with the sole intention of sexually exciting the viewer Urolagnia (also urophilia, undinism) is a Sexual activity in which participants derive sexual pleasure from Urine and/or Urination
Throughout the animal kingdom, urination often serves a utilitarian purpose. In biological Taxonomy, a kingdom or regnum is a Taxonomic rank in either (historically the highest rank or (in the new three-domain system In Economics, utility is a measure of the relative satisfaction from or desirability of Consumption of various Goods and services. In dogs and other animals, urination can mark territory or express submissiveness. The dog ( Canis lupus familiaris) is a domesticated Subspecies of the gray wolf, a Mammal of the Canidae family of the order Territorial marking is Behavior used by Animals to identify their territory. In small rodents such as rats and mice, it marks familiar paths. Rodentia is an order of Mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must
Animals usually kneel, lift or spread legs to complete full urination. Kneeling is a Human position in which the weight is distributed on the Knees and feet on a surface close to horizontal A leg is a limb on an Animal 's Body that supports the rest of the animal above the ground between the Ankle and the Hip and is used for