100-580: Pain is a distressing feeling often caused by intense or damaging stimuli. Pain may also refer to: Pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage." Pain motivates organisms to withdraw from damaging situations, to protect
200-486: A decreased appetite and decreased nutritional intake. A change in condition that deviates from baseline, such as moaning with movement or when manipulating a body part, and limited range of motion are also potential pain indicators. In patients who possess language but are incapable of expressing themselves effectively, such as those with dementia, an increase in confusion or display of aggressive behaviors or agitation may signal that discomfort exists, and further assessment
300-505: A squat toilet is used for urination in a squatting position. Women averting contact with a toilet seat may employ a partial squatting position (or "hovering"), similar to using a female urinal . However, this may not completely void the bladder . Females may also urinate while standing, and while clothed. It is common for women in various regions of Africa to use this position when they urinate, as do women in Laos . Herodotus described
400-403: A contraction of the perineal muscles. The external sphincter can be contracted voluntarily, which will prevent urine from passing down the urethra. The need to urinate is experienced as an uncomfortable, full feeling. It is highly correlated with the fullness of the bladder. In many males the feeling of the need to urinate can be sensed at the base of the penis as well as the bladder, even though
500-488: A credible and convincing signal of the need for relief, help, and care. Idiopathic pain (pain that persists after the trauma or pathology has healed, or that arises without any apparent cause) may be an exception to the idea that pain is helpful to survival, although some psychodynamic psychologists argue that such pain is psychogenic, enlisted as a protective distraction to keep dangerous emotions unconscious. In pain science, thresholds are measured by gradually increasing
600-431: A damaged body part while it heals, and to avoid similar experiences in the future. Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain arises in the absence of any detectable stimulus, damage or disease. Pain is the most common reason for physician consultation in most developed countries. It
700-424: A different phenomenon occurs, where urine is discharged as droplets, and urination in smaller mammals, such as mice and rats, can occur in less than a second. The posited benefits of faster voiding are decreased risk of predation (while voiding) and decreased risk of urinary tract infection. The mechanism by which voluntary urination is initiated remains unsettled. One possibility is that the voluntary relaxation of
800-525: A higher risk of being stigmatized, leading to less urgent treatment of women based on social expectations of their ability to accurately report it. This has been postulated to lead to extended emergency room wait times for women and frequent dismissal of their ability to accurately report pain. Pain is a symptom of many medical conditions. Knowing the time of onset, location, intensity, pattern of occurrence (continuous, intermittent, etc.), exacerbating and relieving factors, and quality (burning, sharp, etc.) of
900-721: A highly desirable option. Women generally need to urinate more frequently than men, but as opposed to the common misconception, it is not due to having smaller bladders. Resisting the urge to urinate because of lack of facilities can promote urinary tract infections which can lead to more serious infections and, in rare situations, can cause renal damage in women. Female urination devices are available to help women to urinate discreetly, as well to help them urinate while standing. Techniques and body postures while urinating vary across cultures. Different anatomical conditions in men and women may presume different postures, yet these are largely shaped by cultural norms, types of clothing, and
1000-404: 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, and may be caused, by infection in the bladder wall. A common technique used in many developing nations involves holding the child by the backs of
1100-454: A non-communicative person, observation becomes critical, and specific behaviors can be monitored as pain indicators. Behaviors such as facial grimacing and guarding (trying to protect part of the body from being bumped or touched) indicate pain, as well as an increase or decrease in vocalizations, changes in routine behavior patterns and mental status changes. Patients experiencing pain may exhibit withdrawn social behavior and possibly experience
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#17330851066721200-463: A place is, the more public urination tends to be objectionable. In the countryside, it is more acceptable than in a street in a town, where it may be a common transgression. Often this is done after the consumption of alcoholic beverages , which causes production of additional urine as well as a reduction of inhibitions . One proposed way to inhibit public urination due to drunkenness is the Urilift , which
1300-474: A public place other than at a public urinal varies with the situation and with customs. Potential disadvantages include a dislike of the smell of urine, and exposure of genitals. It can be avoided or mitigated by going to a quiet place and/or facing a tree or wall if urinating standing up, or while squatting, hiding the back behind walls, bushes, or a tree. Portable toilets (port-a-potties) are frequently placed in outdoor situations where no immediate facility
1400-556: A reduction in negative affect . Across studies, participants that were subjected to acute physical pain in the laboratory subsequently reported feeling better than those in non-painful control conditions, a finding which was also reflected in physiological parameters. A potential mechanism to explain this effect is provided by the opponent-process theory . Before the relatively recent discovery of neurons and their role in pain, various body functions were proposed to account for pain. There were several competing early theories of pain among
1500-707: A result of decreased sensation. A much smaller number of people are insensitive to pain due to an inborn abnormality of the nervous system, known as " congenital insensitivity to pain ". Children with this condition incur carelessly-repeated damage to their tongues, eyes, joints, skin, and muscles. Some die before adulthood, and others have a reduced life expectancy. Most people with congenital insensitivity to pain have one of five hereditary sensory and autonomic neuropathies (which includes familial dysautonomia and congenital insensitivity to pain with anhidrosis ). These conditions feature decreased sensitivity to pain together with other neurological abnormalities, particularly of
1600-448: A state known as pain asymbolia, described as intense pain devoid of unpleasantness, with morphine injection or psychosurgery . Such patients report that they have pain but are not bothered by it; they recognize the sensation of pain but suffer little, or not at all. Indifference to pain can also rarely be present from birth; these people have normal nerves on medical investigations, and find pain unpleasant, but do not avoid repetition of
1700-487: 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's smooth muscle has some inherent contractile activity; however, when its nerve supply
1800-432: Is "pain that extends beyond the expected period of healing". Chronic pain may be classified as " cancer-related " or "benign." Allodynia is pain experienced in response to a normally painless stimulus. It has no biological function and is classified by characteristics of the stimuli as cold, heat, touch, pressure or a pinprick. Phantom pain is pain felt in a part of the body that has been amputated , or from which
1900-696: Is a common, reproducible tool in the assessment of pain and pain relief. The scale is a continuous line anchored by verbal descriptors, one for each extreme of pain where a higher score indicates greater pain intensity. It is usually 10 cm in length with no intermediate descriptors as to avoid marking of scores around a preferred numeric value. When applied as a pain descriptor, these anchors are often 'no pain' and 'worst imaginable pain". Cut-offs for pain classification have been recommended as no pain (0–4mm), mild pain (5–44mm), moderate pain (45–74mm) and severe pain (75–100mm). The Multidimensional Pain Inventory (MPI)
2000-642: Is a major symptom in many medical conditions, and can interfere with a person's quality of life and general functioning. People in pain experience impaired concentration, working memory , mental flexibility , problem solving and information processing speed, and are more likely to experience irritability, depression, and anxiety. Simple pain medications are useful in 20% to 70% of cases. Psychological factors such as social support , cognitive behavioral therapy , excitement, or distraction can affect pain's intensity or unpleasantness. First attested in English in 1297,
2100-493: Is a questionnaire designed to assess the psychosocial state of a person with chronic pain. Combining the MPI characterization of the person with their IASP five-category pain profile is recommended for deriving the most useful case description. Non-verbal people cannot use words to tell others that they are experiencing pain. However, they may be able to communicate through other means, such as blinking, pointing, or nodding. With
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#17330851066722200-475: Is also associated with increased depression, anxiety, fear, and anger. If I have matters right, the consequences of pain will include direct physical distress, unemployment, financial difficulties, marital disharmony, and difficulties in concentration and attention… Although pain is considered to be aversive and unpleasant and is therefore usually avoided, a meta-analysis which summarized and evaluated numerous studies from various psychological disciplines, found
2300-467: Is available. These need to be serviced (cleaned out) on a regular basis. Urination in a heavily wooded area is generally harmless, actually saves water, and may be condoned for males (and less commonly, females) in certain situations as long as common sense is used. Examples (depending on circumstances) include activities such as camping, hiking, delivery driving, cross country running, rural fishing, amateur baseball, golf, etc. The more developed and crowded
2400-410: Is called a diuretic , whereas antidiuretics decrease the production of urine by the kidneys. 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
2500-543: Is caused by stimulation of sensory nerve fibers that respond to stimuli approaching or exceeding harmful intensity ( nociceptors ), and may be classified according to the mode of noxious stimulation. The most common categories are "thermal" (e.g. heat or cold), "mechanical" (e.g. crushing, tearing, shearing, etc.) and "chemical" (e.g. iodine in a cut or chemicals released during inflammation ). Some nociceptors respond to more than one of these modalities and are consequently designated polymodal. Urination Urination
2600-524: Is common. Cultures around the world differ regarding socially accepted voiding positions and preferences: in the Middle-East and Asia, the squatting position was more prevalent, while in the Western world the standing and sitting positions were more common. For practising Muslim men, the genital modesty of squatting is also associated with proper cleanliness requirements or awrah . In Western culture,
2700-454: Is disguised as a normal manhole by day but raises out of the ground at night to provide a public restroom for bar-goers. In many places, public urination is punishable by fines, though attitudes vary widely by country. In general, females are less likely to urinate in public than males. Women and girls, unlike men and boys, are restricted in where they can urinate conveniently and discreetly. The 5th-century BC historian Herodotus , writing on
2800-547: Is distinctly located also activates the primary and secondary somatosensory cortex . Spinal cord fibers dedicated to carrying A-delta fiber pain signals and others that carry both A-delta and C fiber pain signals to the thalamus have been identified. Other spinal cord fibers, known as wide dynamic range neurons , respond to A-delta and C fibers and the much larger, more heavily myelinated A-beta fibers that carry touch, pressure, and vibration signals. Ronald Melzack and Patrick Wall introduced their gate control theory in
2900-470: Is essential for protection from injury, and recognition of the presence of injury. Episodic analgesia may occur under special circumstances, such as in the excitement of sport or war: a soldier on the battlefield may feel no pain for many hours from a traumatic amputation or other severe injury. Although unpleasantness is an essential part of the IASP definition of pain, it is possible in some patients to induce
3000-403: Is initially described as burning or tingling but may evolve into severe crushing or pinching pain, or the sensation of fire running down the legs or of a knife twisting in the flesh. Onset may be immediate or may not occur until years after the disabling injury. Surgical treatment rarely provides lasting relief. Breakthrough pain is transitory pain that comes on suddenly and is not alleviated by
3100-493: 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. Since bladder wall stretch is low during the storage phase, these afferent neurons fire at low frequencies. Low-frequency afferent signals cause relaxation of
Pain (disambiguation) - Misplaced Pages Continue
3200-507: Is necessary. Changes in behavior may be noticed by caregivers who are familiar with the person's normal behavior. Infants do feel pain , but lack the language needed to report it, and so communicate distress by crying. A non-verbal pain assessment should be conducted involving the parents, who will notice changes in the infant which may not be obvious to the health care provider. Pre-term babies are more sensitive to painful stimuli than those carried to full term. Another approach, when pain
3300-421: Is often described as shooting, crushing, burning or cramping. If the pain is continuous for a long period, parts of the intact body may become sensitized, so that touching them evokes pain in the phantom limb. Phantom limb pain may accompany urination or defecation . Local anesthetic injections into the nerves or sensitive areas of the stump may relieve pain for days, weeks, or sometimes permanently, despite
3400-451: Is possible for both sexes to urinate into bottles in case of emergencies. The technique can help children to urinate discreetly inside cars and in other places without being seen by others. A female urination device can assist women and girls in urinating while standing or into a bottle. In microgravity , excrement tends to float freely, so astronauts use a specially designed space toilet , which uses suction to collect and recycle urine;
3500-412: Is suspected, is to give the person treatment for pain, and then watch to see whether the suspected indicators of pain subside. The way in which one experiences and responds to pain is related to sociocultural characteristics, such as gender, ethnicity, and age. An aging adult may not respond to pain in the same way that a younger person might. Their ability to recognize pain may be blunted by illness or
3600-506: Is the process of learning to restrict urination to socially approved times and situations. Consequently, young children sometimes develop nocturnal enuresis . It is socially more accepted and more environmentally hygienic for those who are able, especially when indoors and in outdoor urban or suburban areas, to urinate in a toilet . Public toilets may have urinals , usually for males, although female urinals exist, designed to be used in various ways. Acceptability of outdoor urination in
3700-545: Is the release of urine from the bladder to the outside of the body. Urine is released through the urethra and exits the penis or vulva through the urinary meatus in placental mammals , but is released through the cloaca in other vertebrates . It is the urinary system 's form of excretion . It is also known medically as micturition , voiding , uresis , or, rarely, emiction , and known colloquially by various names including peeing , weeing , pissing , and euphemistically number one . The process of urination
3800-418: Is under voluntary control in healthy humans and other animals , but may occur as a reflex in infants, some elderly individuals, and those with neurological injury. It is normal for adult humans to urinate up to seven times during the day. In some animals, in addition to expelling waste material, urination can mark territory or express submissiveness . Physiologically, urination involves coordination between
3900-523: The autonomic nervous system . A very rare syndrome with isolated congenital insensitivity to pain has been linked with mutations in the SCN9A gene, which codes for a sodium channel ( Na v 1.7 ) necessary in conducting pain nerve stimuli. Experimental subjects challenged by acute pain and patients in chronic pain experience impairments in attention control, working memory capacity , mental flexibility , problem solving, and information processing speed. Pain
4000-453: The central , autonomic , and somatic nervous systems . Brain centres that regulate urination include the pontine micturition center , periaqueductal gray , and the cerebral cortex . The main organs involved in urination are the urinary bladder and the urethra . 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
4100-405: The medial , paleospinothalamic tract . The neospinothalamic tract carries the fast, sharp A-delta signal to the ventral posterolateral nucleus of the thalamus . The paleospinothalamic tract carries the slow, dull C fiber pain signal. Some of the paleospinothalamic fibers peel off in the brain stem—connecting with the reticular formation or midbrain periaqueductal gray—and the remainder terminate in
Pain (disambiguation) - Misplaced Pages Continue
4200-407: The pontine micturition center and, like defecation , subject to voluntary facilitation and inhibition. In healthy individuals, the lower urinary tract has two discrete phases of activity: the storage (or guarding) 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
4300-479: The sacral spinal cord. 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 male or female external urethral sphincter , which is innervated by the somatic pudendal nerve originating in the cord, in an area termed Onuf's nucleus . Smooth muscle bundles pass on either side of
4400-550: The standing position is regarded as the more efficient option among healthy males. In restrooms without urinals, and sometimes at home, men may be urged to use the sitting position as to diminish spattering of urine. Elderly males with prostate gland enlargement may benefit from sitting down to urinate, with the seated voiding position found superior as compared with standing in elderly males with benign prostate hyperplasia . In Western culture, females usually sit or squat for urination, depending on what type of toilet they use;
4500-467: The 1965 Science article "Pain Mechanisms: A New Theory". The authors proposed that the thin C and A-delta (pain) and large diameter A-beta (touch, pressure, vibration) nerve fibers carry information from the site of injury to two destinations in the dorsal horn of the spinal cord, and that A-beta fiber signals acting on inhibitory cells in the dorsal horn can reduce the intensity of pain signals sent to
4600-447: The 19th-century development of specificity theory . Specificity theory saw pain as "a specific sensation, with its own sensory apparatus independent of touch and other senses". Another theory that came to prominence in the 18th and 19th centuries was intensive theory , which conceived of pain not as a unique sensory modality, but an emotional state produced by stronger than normal stimuli such as intense light, pressure or temperature. By
4700-415: The C fibers. These A-delta and C fibers enter the spinal cord via Lissauer's tract and connect with spinal cord nerve fibers in the central gelatinous substance of the spinal cord . These spinal cord fibers then cross the cord via the anterior white commissure and ascend in the spinothalamic tract . Before reaching the brain, the spinothalamic tract splits into the lateral , neospinothalamic tract and
4800-687: The UK, although British cultural tradition itself seems to find such practices objectionable. In Islamic toilet etiquette , it is haram to urinate while facing the Qibla , or to turn one's back to it when urinating or relieving bowels, but modesty requirements for females make it impossible for girls to relieve themselves without facilities. When toilets are unavailable, females can relieve themselves in Laos , Russia and Mongolia in emergency, but it remains less accepted for females in India even when circumstances make this
4900-408: The adult, the volume of urine in the bladder that normally initiates a reflex contraction is about 300–400 millilitres (11–14 imp fl oz; 10–14 US fl oz). 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
5000-429: The affective-motivational dimension. Thus, excitement in games or war appears to block both the sensory-discriminative and affective-motivational dimensions of pain, while suggestion and placebos may modulate only the affective-motivational dimension and leave the sensory-discriminative dimension relatively undisturbed. (p. 432) The paper ends with a call to action: "Pain can be treated not only by trying to cut down
5100-407: The ancient Greeks: Hippocrates believed that it was due to an imbalance in vital fluids . In the 11th century, Avicenna theorized that there were a number of feeling senses, including touch, pain, and titillation. In 1644, René Descartes theorized that pain was a disturbance that passed along nerve fibers until the disturbance reached the brain. The work of Descartes and Avicenna prefigured
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#17330851066725200-423: The bladder becomes full, afferent firing increases, yet the micturition reflex can be voluntarily inhibited until it is appropriate to begin voiding. 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
5300-410: The bladder by inhibiting sacral parasympathetic 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. Diuresis (production of urine by the kidney) occurs constantly, and as
5400-403: The bladder is empty. Many men, and some women, may sometimes briefly shiver after or during urination. After urination, the female urethra empties partially by gravity, with assistance from muscles. Urine remaining in the male urethra is expelled by several contractions of the bulbospongiosus muscle , and, by some men, manual squeezing along the length of the penis to expel the rest of
5500-410: The bladder is flaccid and unresponsive. It becomes overfilled, and urine dribbles through the sphincters ( overflow incontinence ). After spinal shock has passed, a spinally mediated voiding reflex ensues, although there is no voluntary control and no inhibition or facilitation from higher centers. Some paraplegic patients train themselves to initiate voiding by pinching or stroking their thighs, provoking
5600-446: The bladder is fully distended the superficial cells become squamous (flat) and the stratification of the cuboidal cells 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 such as
5700-442: 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 ,
5800-420: The brain and the firing rate of sensory fibers from the bladder and urethra. At low bladder volumes, afferent firing is low, resulting in excitation of the outlet (the sphincter and urethra), and relaxation of the bladder. At high bladder volumes, afferent firing increases, causing a conscious sensation of urinary urge. Individual ready to urinate consciously initiates voiding, causing the bladder to contract and
5900-471: The brain no longer receives signals. It is a type of neuropathic pain. The prevalence of phantom pain in upper limb amputees is nearly 82%, and in lower limb amputees is 54%. One study found that eight days after amputation, 72% of patients had phantom limb pain, and six months later, 67% reported it. Some amputees experience continuous pain that varies in intensity or quality; others experience several bouts of pain per day, or it may reoccur less often. It
6000-506: The brain. In 1968, Ronald Melzack and Kenneth Casey described chronic pain in terms of its three dimensions: They theorized that pain intensity (the sensory discriminative dimension) and unpleasantness (the affective-motivational dimension) are not simply determined by the magnitude of the painful stimulus, but "higher" cognitive activities can influence perceived intensity and unpleasantness. Cognitive activities may affect both sensory and affective experience, or they may modify primarily
6100-413: The brain. 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. These people (males) may have difficulty urinating in
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#17330851066726200-547: The cerebrum. At a certain level of afferent activity, the conscious urge to void or urination urgency , becomes difficult to ignore. Once the voluntary signal to begin voiding has been issued, neurons in the 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 intravesical pressure occurs. The pontine micturition center also causes inhibition of Onuf's nucleus, resulting in relaxation of
6300-495: The culture of the ancient Persians and highlighting the differences with those of the Greeks , noted that to urinate in the presence of others was prohibited among Persians. There was a popular belief in the UK, that it was legal for a man to urinate in public so long as it occurred on the rear wheel of his vehicle and he had his right hand on the vehicle, but this is not true. Public urination still remains more accepted by males in
6400-418: The detrusor muscle to contract and the internal urethral sphincter to relax. 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 by the age of two–three years, as control at higher levels of the central nervous system develops. In
6500-413: The drug wearing off in a matter of hours; and small injections of hypertonic saline into the soft tissue between vertebrae produces local pain that radiates into the phantom limb for ten minutes or so and may be followed by hours, weeks, or even longer of partial or total relief from phantom pain. Vigorous vibration or electrical stimulation of the stump, or current from electrodes surgically implanted onto
6600-416: The external urinary sphincter. When the external urinary sphincter is relaxed urine is released from the urinary bladder when the pressure there is great enough to force urine to flow out of 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
6700-400: The intensity of a stimulus in a procedure called quantitative sensory testing which involves such stimuli as electric current , thermal (heat or cold), mechanical (pressure, touch, vibration), ischemic , or chemical stimuli applied to the subject to evoke a response. The " pain perception threshold " is the point at which the subject begins to feel pain, and the "pain threshold intensity" is
6800-400: The intralaminar nuclei of the thalamus. Pain-related activity in the thalamus spreads to the insular cortex (thought to embody, among other things, the feeling that distinguishes pain from other homeostatic emotions such as itch and nausea) and anterior cingulate cortex (thought to embody, among other things, the affective/motivational element, the unpleasantness of pain), and pain that
6900-422: 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
7000-416: The likelihood of reporting pain. Patients may feel that certain treatments go against their religious beliefs. They may not report pain because they feel it is a sign that death is near. Many people fear the stigma of addiction, and avoid pain treatment so as not to be prescribed potentially addicting drugs. Many Asians do not want to lose respect in society by admitting they are in pain and need help, believing
7100-575: The mid-1890s, specificity was backed primarily by physiologists and physicians, and psychologists mostly backed the intensive theory . However, after a series of clinical observations by Henry Head and experiments by Max von Frey , the psychologists migrated to specificity almost en masse. By the century's end, most physiology and psychology textbooks presented pain specificity as fact. Some sensory fibers do not differentiate between noxious and non-noxious stimuli, while others (i.e., nociceptors ) respond only to noxious, high-intensity stimuli. At
7200-415: The muscles of the pelvic floor causes a sufficient downward tug on the detrusor muscle to initiate its contraction. 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. There is an inhibitory area for micturition in the midbrain. After transection of the brain stem just above
7300-511: The neural activity associated with a full bladder comes from the bladder itself, and can be felt there as well. In females the need to urinate is felt in the lower abdomen region when the bladder is full. When the bladder becomes too full, the sphincter muscles will involuntarily relax, allowing urine to pass from the bladder. Release of urine is experienced as a lessening of the discomfort. Many clinical conditions can cause disturbances to normal urination, including: A drug that increases urination
7400-480: The noxious stimulus is removed or the underlying damage or pathology has healed. But some painful conditions, such as rheumatoid arthritis , peripheral neuropathy , cancer , and idiopathic pain, may persist for years. Pain that lasts a long time is called " chronic " or "persistent", and pain that resolves quickly is called " acute ". Traditionally, the distinction between acute and chronic pain has relied upon an arbitrary interval of time between onset and resolution;
7500-451: 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. The muscles controlling micturition are controlled by the autonomic and somatic nervous systems. During the storage phase, the internal urethral sphincter remains tense and the detrusor muscle relaxed by sympathetic stimulation. During micturition, parasympathetic stimulation causes
7600-400: The pain should be borne in silence, while other cultures feel they should report pain immediately to receive immediate relief. Gender can also be a perceived factor in reporting pain. Gender differences can be the result of social and cultural expectations, with, in some cultures, women expected to be more emotional and show pain, and men to be more stoic. As a result, female pain may be at
7700-487: The pain stimulus. Insensitivity to pain may also result from abnormalities in the nervous system . This is usually the result of acquired damage to the nerves, such as spinal cord injury , diabetes mellitus ( diabetic neuropathy ), or leprosy in countries where that disease is prevalent. These individuals are at risk of tissue damage and infection due to undiscovered injuries. People with diabetes-related nerve damage, for instance, sustain poorly-healing foot ulcers as
7800-400: The pain will help the examining physician to accurately diagnose the problem. For example, chest pain described as extreme heaviness may indicate myocardial infarction , while chest pain described as tearing may indicate aortic dissection . Functional magnetic resonance imaging brain scanning has been used to measure pain, and correlates well with self-reported pain. Nociceptive pain
7900-497: The patient's regular pain management . It is common in cancer patients who often have background pain that is generally well-controlled by medications, but who also sometimes experience bouts of severe pain that from time to time "breaks through" the medication. The characteristics of breakthrough cancer pain vary from person to person and according to the cause. Management of breakthrough pain can entail intensive use of opioids , including fentanyl . The ability to experience pain
8000-512: The peripheral end of the nociceptor, noxious stimuli generate currents that, above a given threshold, send signals along the nerve fiber to the spinal cord. The "specificity" (whether it responds to thermal, chemical, or mechanical features of its environment) of a nociceptor is determined by which ion channels it expresses at its peripheral end. So far, dozens of types of nociceptor ion channels have been identified, and their exact functions are still being determined. The pain signal travels from
8100-486: The periphery to the spinal cord along A-delta and C fibers. Because the A-delta fiber is thicker than the C fiber, and is thinly sheathed in an electrically insulating material ( myelin ), it carries its signal faster (5–30 m/s ) than the unmyelinated C fiber (0.5–2 m/s). Pain evoked by the A-delta fibers is described as sharp and is felt first. This is followed by a duller pain—often described as burning—carried by
8200-512: 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
8300-527: The presence of others and will consequently avoid using urinals without dividers or those directly adjacent to another person. Alternatively, they may opt for the privacy of a stall or simply avoid public toilets altogether. 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
8400-453: 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. Voiding can also be consciously interrupted once it has begun, through
8500-474: The question of why pain should have the quality of being painful. He describes the alternative as a mental raising of a "red flag". To argue why that red flag might be insufficient, Dawkins argues that drives must compete with one another within living beings. The most "fit" creature would be the one whose pains are well balanced. Those pains which mean certain death when ignored will become the most powerfully felt. The relative intensities of pain, then, may resemble
8600-537: The relative importance of that risk to our ancestors. This resemblance will not be perfect, however, because natural selection can be a poor designer . This may have maladaptive results such as supernormal stimuli . Pain, however, does not only wave a "red flag" within living beings but may also act as a warning sign and a call for help to other living beings. Especially in humans who readily helped each other in case of sickness or injury throughout their evolutionary history, pain might be shaped by natural selection to be
8700-579: The sanitary facilities available. While sitting toilets are the most common form in Western countries, squat toilets are common in Asia , Africa , and the Arab world . Urinals for men are widespread worldwide, although women's urinals are available in some countries, recently becoming more common in Western countries. With the spread of pants among women, a standing posture became impractical, but in some regions where women wear traditional skirts or robes, an upright posture
8800-654: The sensory input by anesthetic block, surgical intervention and the like, but also by influencing the motivational-affective and cognitive factors as well." (p. 435) Pain is part of the body's defense system, producing a reflexive retraction from the painful stimulus, and tendencies to protect the affected body part while it heals, and avoid that harmful situation in the future. It is an important part of animal life, vital to healthy survival. People with congenital insensitivity to pain have reduced life expectancy . In The Greatest Show on Earth: The Evidence for Evolution , biologist Richard Dawkins addresses
8900-495: The space toilet also has a receptacle for defecation. A puer mingens is a figure in a work of art depicted as a prepubescent boy in the act of urinating, either actual or simulated. The puer mingens could represent anything from whimsy and boyish innocence to erotic symbols of virility and masculine bravado. Babies have little socialized control over urination within traditions or families that do not practice elimination communication and instead use diapers . Toilet training
9000-535: The spinal cord, all produce relief in some patients. Mirror box therapy produces the illusion of movement and touch in a phantom limb which in turn may cause a reduction in pain. Paraplegia , the loss of sensation and voluntary motor control after serious spinal cord damage, may be accompanied by girdle pain at the level of the spinal cord damage, visceral pain evoked by a filling bladder or bowel, or, in five to ten percent of paraplegics, phantom body pain in areas of complete sensory loss. This phantom body pain
9100-408: The stimulus intensity at which the stimulus begins to hurt. The " pain tolerance threshold" is reached when the subject acts to stop the pain. A person's self-report is the most reliable measure of pain. Some health care professionals may underestimate pain severity. A definition of pain widely employed in nursing, emphasizing its subjective nature and the importance of believing patient reports,
9200-442: The thighs, above the ground, facing outward, in order to urinate. The fetus urinates hourly and produces most of the amniotic fluid in the second and third trimester of pregnancy. The amniotic fluid is then recycled by fetal swallowing. 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
9300-460: The two most commonly used markers being 3 months and 6 months since the onset of pain, though some theorists and researchers have placed the transition from acute to chronic pain at 12 months. Others apply "acute" to pain that lasts less than 30 days, "chronic" to pain of more than six months' duration, and "subacute" to pain that lasts from one to six months. A popular alternative definition of "chronic pain", involving no arbitrarily fixed duration,
9400-412: The urethra to a location where urination can still be accomplished, usually in a position that would promote urination only while seated/squatting, though a permanent urinary catheter may be used in rare cases. Sometimes urination is done in a container such as a bottle, urinal , bedpan, or chamber pot (also known as a gazunder ). A container or wearable urine collection device may be used so that
9500-456: The urethra, and these fibers are sometimes called the internal urethral sphincter , although they do not encircle the urethra. Further 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. When
9600-421: The urine can be examined for medical reasons or for a drug test , for a bedridden patient, when no toilet is available, or there is no other possibility to dispose of the urine immediately. An alternative solution (for traveling, stakeouts , etc.) is a special disposable bag containing absorbent material that solidifies the urine within seconds, making it convenient and safe to store and dispose of later. It
9700-443: The urine. For land mammals over 1 kilogram, the duration of urination does not vary with body mass, being dispersed around an average of 21 seconds (standard deviation 13 seconds), despite a 4 order of magnitude (1000×) difference in bladder volume. This is due to increased urethra length of large animals, which amplifies gravitational force (hence flow rate), and increased urethra width, which increases flow rate. For smaller mammals
9800-410: The use of medication . Depression may also keep older adult from reporting they are in pain. Decline in self-care may also indicate the older adult is experiencing pain. They may be reluctant to report pain because they do not want to be perceived as weak, or may feel it is impolite or shameful to complain, or they may feel the pain is a form of deserved punishment. Cultural barriers may also affect
9900-542: The word peyn comes from the Old French peine , in turn from Latin poena meaning "punishment, penalty" (also meaning "torment, hardship, suffering" in Late Latin) and that from Greek ποινή ( poine ), generally meaning "price paid, penalty, punishment". The International Association for the Study of Pain recommends using specific features to describe a patient's pain: Pain is usually transitory, lasting only until
10000-542: Was introduced by Margo McCaffery in 1968: "Pain is whatever the experiencing person says it is, existing whenever he says it does". To assess intensity, the patient may be asked to locate their pain on a scale of 0 to 10, with 0 being no pain at all, and 10 the worst pain they have ever felt. Quality can be established by having the patient complete the McGill Pain Questionnaire indicating which words best describe their pain. The visual analogue scale
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