P. Hunter Peckham, ... Christa W. Moss, in Biomaterials scientific research (Third Edition), 2013

Disc Electrodes

The ingredient of the micturition circuit at first targeted for electrical stimulation v an implanted, RF powered machine was the bladder wall surface muscle. Susset and Boctor reported success v an implant that incorporated 8 disc electrodes approximately the dome that the bladder that an individual with lower motorneuron (LMN) injury (Susset and Boctor, 1967). However, in individuals with a neurogenic bladder (spastic through contractions prompted at short filling volumes) from spinal cord injury, this therapy was not successful, because bladder stimulation also activated the urethral sphincter, preventing voiding in this population (Gaunt and also Prochazka, 2009).

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Ureteral Delivery and also Efflux


PABLO A. MORALES, in Urodynamics, 1971

Ureteral activity in an answer to changes in Intravesical Pressure throughout Bladder Filling

Ureteral task during bladder filling and micturition was studied in nine normal subjects. Ureteral pressures were measured with No. 4F cardiac catheters. 2 catheters were introduced through a 21F Brown–Buerger cystoscope and also inserted into the exact same ureter, one to a level that 15–17 centimeter from the orifice, and the various other to a level that 5–7 centimeter from the orifice. Both to be then linked at their distal end to separate push transducers. The cystoscope was attached come a water manometer for intravesical pressure determinations.

Pressure fluctuations from the midureter and also lower ureter were all at once graphed on a Sanborn dual-pressure recorder. Zero level was assumed come be at the symphysis pubis. The videotaped pressure alters during a peristaltic contraction of the ureter constitute a contraction complex. There may be one or more spikes in the convulsion phase, and the highest suggest is called the peak. The press level in in between contraction complexes is the intraureteral resting pressure. Contraction amplitude is referred to as complete contraction pressure.

Simultaneous baseline recordings of midureteral, low-ureteral, and intravesical pressure were first obtained through the bladder in an north state. Increments that 25–50 ml water were climate introduced into the bladder, and the equivalent pressure fluctuations were recorded. Bladder pour it until it is full was continued until voiding occurred. Recordings were, likewise, derived during micturition.


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J.R. Ajmeri, C.J. Ajmeri, in Applications of Nonwovens in technological Textiles, 2010

Medium–low incontinence

The main functional needs are to absorb urine during micturition and distribute the urine throughout the absorption pad, administer medium capacity absorption, retain urine efficiently in the absorbent core, isolate wetness indigenous the skin, and reduce potential odor troubles caused by urine degradation. Important and desired properties room maximizing wearer comfort, great product fit, an excellent level that discreetness v the product, and also a high level the hygiene. The framework of these products is similar to feminine hygiene products like restroom pads and panty liners, but they are specifically designed for incontinence with advanced leakage protection for urine. These products are sandwich-structured through an absorbent core consisting of a mix of fiberized fluff pulp and SAP.116 The topsheet is a great of PE or PP nonwovens or deserve to be a mix that both. The ago sheet is typically composed the a PE movie or a nonwoven/film composite, which might be breathable. It stays clear of wetness move to the clothes. The product is fastened to the underwear by one adhesive piece on the ago sheet, defended by release document prior to use.


Joseph Feher, in Quantitative human being Physiology, 2012

Micturition involves Autonomic Reflexes and Volitional worried Activity

The urinary bladder is a muscular sac the stores in between 150 and 250 mL of urine created by the kidneys until it deserve to be voided. The capacity to hold urine in the bladder is referred to as continence and emptying the bladder is referred to as micturition. Micturition have the right to occur immediately by a spinal reflex, yet it have the right to be overridden by greater control. Reflex convulsion of the detrusor muscle in the bladder is managed by afferent stretch receptor in the walls of the bladder that travel over the pelvic nerve to the sacral spinal cord (S2–S4) whereby they communicate efferent fibers. Details from this stretch receptor ascends the cord to make us consciously aware of the should urinate. Simultaneously, parasympathetic efferents relax the inner sphincter muscle ~ above the urethra.

Sympathetic yarn originating in the intermediolateral horn in the distal thoracic and also lumbar spinal cord travel to the worse mesenteric ganglion where they synapse ~ above postganglionic forgiveness fibers. These fibers travel in the hypogastric nerve come the bladder wherein they inhibit the detrusor muscle v β2-receptors and also contract the interior sphincter muscle with α1-receptors. The sorry fibers additionally inhibit the large reflex with intraspinal connections. The sympathetic system inhibits bladder emptying vice versa, the parasympathetic mechanism promotes it.

Nearly everyone has at once or another found themselves with a complete bladder through no socially acceptable means of relieving themselves. The just recourse is to “hold it” till a ideal place is found. This is the function of the external sphincter muscles the are controlled by somatic α engine neurons in the sacral spinal cord that reach the outside sphincter muscle end the pudendal nerve. These motor neurons space under mindful control through higher centers and also through spinal tracts.


A micturition center in the rostral pons obtain input native the cortex, cerebellum, and also other centers over the pons and also controls micturition v the reticulospinal tract. This center can be either activated, come void the bladder, or suppressed come inhibit micturition. Number 4.9.9 mirrors the results of nervous task that disclosure micturition. To promote micturition, the micturition center inhibits sympathetic calculation to remove inhibition the detrusor contraction and also contraction the the internal sphincter. Simultaneously, it strengthens the spinal stretch reflex and also inhibits somatic motor neuron contraction of the outside sphincter. Every one of these actions result in contraction of the detrusor muscle and also relaxation that the sphincters.



Figure 4.9.9. Parasympathetic and also sympathetic regulate of micturition. Stretch receptors in the wall surface of the bladder activate a parasympathetic urination reflex in the sacral spinal cord. The parasympathetic afferents and efferents both take trip over the pelvic nerve. The efferent parasympathetics contract the detrusor muscle that empties the bladder and also relaxes the inner sphincter. Sorry efferents originate in the intermediolateral gray shaft of T10–L2 and also travel to the inferior mesenteric ganglion. The hypogastric nerve carries the sorry efferents come the bladder whereby they encourage relaxation the the detrusor and also contraction of the internal sphincter. One intraspinal tract from the intermediolateral sympathetics additionally inhibits the sacral micturition reflex. Micturition can be overridden by conscious control the somatic α-motor neurons in the ventral horn of the sacral spinal cord. Efferent signals from the engine neuron take trip over the pudendal nerve come contract the outside sphincter. The micturition center located in the rostral pons obtain inputs indigenous the cerebrum, cerebellum, and other superpontine centers. It collaborates the parasympathetic, sympathetic, and also somatic motor control of micturition. The sympathetic yarn are shown in blue; parasympathetics space in black; somatic engine neuron in special black. The effects displayed are for promo of micturition; a hopeful sign indicates excitation, a an adverse sign suggests inhibition. The all at once effect of any type of pathway deserve to be determined by multiply the signs. Hence the parasympathetic micturition reflex is big receptor (+) × interneuron (+) × preganglionic fiber (+) × postganglionic fiber ~ above detrusor (+)=detrusor convulsion (+).


The control of defecation complies with the same simple principles together the manage of micturition.


Clinical Applications: Nerve Gases

Nerve gases tie to and inhibit acetylcholinesterase. As a result, all cholinergic synapses room chronically stimulated due to the fact that the neurotransmitter, acetylcholine, is not properly hydrolyzed adhering to excitation. The result symptoms depend somewhat top top the sheep of poison. All cholinergic parasympathetic effects are activated: salivation, lacrimation, urination, defecation, emesis, (SLUDE), bronchial secretion, bronchioconstriction, and bradycardia. Various other cholinergic synapses are likewise activated, producing sweating, muscle spasm, and effective paralysis. The agents impact both the respiratory tract center and also the respiratory muscles so that death typically occurs through suffocation. In ~ high doses, victims may lose consciousness and also convulse, and also death may happen so quickly that the parasympathetic results may not have actually time come develop. Thus, these nerve gases kill by jamming the off switch come cholinergic neurotransmission.

The most essential nerve gases room Sarin and also VX, who chemical structures are shown below. Sarin was an initial produced by the Germans in 1938 and also named because that the four scientists who uncovered it: Schrader, Ambros, Rudinger, and Linde. By the end of the war the German military had 30 tons the it. Allied armed forces planners suspect the gas would be used, and Britain had stockpiled 30 million gas masks in preparation for the event. Fortunately, Germany never ever used Sarin during world War II, probably in are afraid of choose retaliation and also because that dispersal is not easily controlled. Its only well-known use was by the Japanese cult Aum Shinrikyo, who dropped plastic bags wrapped in newspaper on five separate subway trains in Tokyo on march 20, 1995. The bags were punctured by sharpened umbrella advice in a coordinated attack. The fluid leaked out and vaporized, poisoning several thousand commuters and also killing 12.

British chemistry made VX in 1952 in ~ the Porton Down tools Research facility in Wiltshire. Castle traded information about its approaches to the United says in return for tricks on thermonuclear weapons. This nasty chemical has the advantage of gift stable and so have the right to contaminate areas for much longer times. The British exit nerve agents in donate of thermonuclear weapons. The LD50 (the dose that kills 50% that those exposed) because that VX is 10 mg.

The term “nerve gas” is something of a misnomer since the agents are liquids at ambient temperatures and also pressures. However, they can be distributed as gas or aerosols, and also the liquid form is readily soaked up through the skin.

One antidote because that these nerve agents is atropine. This does no reverse the effect of the agents, yet blocks the effects of excess acetylcholine neurotransmitters. The dose is around 1 mg. A 2nd agent, pralidoxime chloride, is component of the note I Kit issued come the U.S. Military and also contains 600 mg. Pralidoxime rescues the acetylcholinesterase indigenous nerve certified dealer inhibition.

Who has actually nerve agents, in what quantities, and with what distribution capabilities, is a inquiry for knowledge Agencies. The unified States and also Russia have admitted to having actually stockpiles that VX, and also both are committed to destroying them. Although there is no proof, some case that Iraq provided nerve agents in assaults on the Kurds in Halabja in northern Iraq in 1988.

Clinical Applications: Muscarine Poisoning

Eating mushrooms can be a tricky business because some room poisonous. The mushroom Amanita muscaris makes an alkaloid poison dubbed muscarine, whose structure is shown below. Keep in mind that it has some structural similarities to acetylcholine, shown next come it. Since of its structure similarity come acetylcholine, muscarine can bind come the acetylcholine receptor and activate it. Thus, muscarine is a cholinergic agonist. Muscarine acts on the muscarinic receptors, yet not ~ above the nicotinic receptors. The chemical structure of nicotine is presented for comparison. However, muscarine go not have actually the acetyl ester team that is hydrolyzed by acetylcholinesterase, therefore its stimulation cannot be shut off by hydrolysis. Instead, muscarine is slowly cleared from the body by urinary excretion.

Muscarine poisoning reasons a chronic stimulation of the muscarinic receptors. These are mostly on target cells of parasympathetic stimulation. Their impacts include stimulation that glandular secretions including tearing, salivation, sweating, and nasal and bronchial secretions. Smooth muscle of the intestinal tract is stimulated, leading to both defecation and also emesis. The urinary bladder contracts and also the sphincter relaxes, resulting in urination. Constriction of the bronchioles makes it an overwhelming to breathe, and the heart rate slows (bradycardia). The is completely a nasty business.

Fortunately, over there is help. An additional plant, the deadly nightshade, Atropa belladona, produces one more poison called atropine, who chemical structure is presented above. This chemical is a muscarinic receptor antagonist, and it blocks the impacts of muscarine. One result of parasympathetic stimulation is constriction the the pupillary sphincter muscle, i beg your pardon constricts the pupil. Ordinarily, this wake up in an answer to bright light to border the irradiate intensity top top the retina. Prevent this impact with atropine therefore dilates the pupils. Females in Europe found this effect and administered that to us to appear an ext attractive. For this reason the tree was named “belladona,” an interpretation “beautiful lady.” back atropine deserve to block the results of muscarine, it is a toxicity in its very own right.

T. Louwies, B. Greenwood-Van Meerveld, in recommendation Module in Biomedical Sciences, 2021

5.2.4 Cross-sensitization

Under normal circumstances, the bladder and also colon room functionally related. Because that instance, micturition and defecation room alternated, and also colonic distension will inhibit voluntarily bladder contractility. However, this functional connection may additionally contribute to pathological conditions, when significant overlap in symptoms in between bladder (IC/PBS) and colonic disorders (IBS and also IBS) becomes apparent. Furthermore, fibromyalgia, a somatic ache disorder, is a typical comorbidity in IBS, IBD and also IC/PBS (Lubrano et al., 2001; Buskila et al., 1999; Chelimsky et al., 2012). The overlap of symptoms and also comorbidities are because of viscero-visceral and viscero-somatic cross-sensitization. Cross-sensitization is possible when second order neurons of the pain pathway obtain convergent entry from various visceral and somatic offal (Ness and also Gebhart, 1990; Gebhart and also Ness, 1991). Cross-organ sensitization is the factor why ab pain is frequently referred come somatic sites and why visceral pain has actually long been puzzled with somatic pain. Furthermore, cross-sensitization that visceral guts poses significant problems in diagnosing and treating the diseased organ.

The mechanisms for viscero-visceral and viscero-somatic organ cross-sensitization are situated in the periphery and also the CNS. Dichotomizing major afferents have actually sensory endings situated in two various organs. Through injecting two various retrogradely transported dyes in different organs, dichotomizing fibers have actually been defined innervating colon, anus and lower urinary street (Bahns et al., 1986). These neurons are expressing the pro-nociceptive receptors TRPV1 and P2X3 (Brederson and also Jarvis, 2008; wide et al., 2009). In rat DRGs, colonic inflammation leads to upregulation that CGRP in these fibers, which reflects that they space likely involved in pain transmission and also sensitization. Injury or inflammation in one of the target organs deserve to sensitize dichotomizing neurons, which normally leads to cross-sensitization. As soon as considering dichotomizing afferents are the primary reason because that cross-organ sensitization, one must be mindful that the actual variety of dichotomizing sensory neurons in the DRG is a rather tiny percentage that the total variety of visceral afferents. Furthermore, the actual number likewise seems to vary widely in between animals and studies, varying from 0.1% to 21% of all traced neurons in these research studies (Brumovsky and also Gebhart, 2010). In addition to dichotomizing neurons, cross-sensitization could happen through electrical or chemical coupling the neurons. As result of their close anatomical proximity, DRG neurons room electrically coupled through void junctions. Intraganglionic relax of SP, CGRP, or inflammation mediators indigenous a sensitized neuron deserve to trigger second messenger equipment of non-sensitized neighboring neurons. Cross-sensitization can also occur when various visceral and somatic afferents converge on the same second order neuron in the spinal cord. In addition, visceral and somatic afferent input have the right to converge at the level that the brainstem and thalamus (Hubscher et al., 2004; Rouzade-Dominguez et al., 2003a,b; Hubscher and Johnson, 2003). Because that instance, neurons in Barrington's nucleus, located in the brainstem, that regulate micturition, respond to both bladder and also colon distension. On the molecule level, spinal and supraspinal cross-sensitization are mediated through TRPV1, glutamate and also upregulation the phosphorylated NMDA receptor subunit N-methyl-d-aspartate receptor subtype 2B (NR2B) in spinal neurons (Peng et al., 2008a,b, 2009).

In the situation of patients enduring from IBS, IBD or IC/PBS, inflammation or injury in the bladder or colon have the right to enhance the excitability the dichotomizing and also non-dichotomizing primary sensory afferents. V the production and also release of inflammatory mediators or secondary messengers and/or electrical coupling, the sensitized neuron deserve to increase excitability of primary afferents the innervate the non-affected organ. Consequently, sensitized main neurons will rise the release of neurotransmitters onto second order neurons in the dorsal horn that the spinal cord, leading to viscero-visceral cross-organ sensitization. As these spinal neurons also receive convergent input from somatic afferents, this might lead to viscero-somatic cross-sensitization. As a result, patients will suffer incoming visceral and somatic sensory signals as painful, having many challenges to decide the precise organ that is responsible for the pain.


GORDON F. ANDERSON, ... CHRISTOPHER M. FREDERICKS, in Urodynamics, 1971

Publisher Summary

This chapter discusses the ureteral solution to bladder filling. The pressure in bladder press is raised before and also during micturition, the ureteral frequency increased and following micturition ended up being readjusted to a normal price or had actually a compensatory slowing. Once the bladder press reaches the point at which the forces compelled to move urine v the ureterovesical orifice space great, the ureter shows up to conquer this in two ways. The an initial is raised peristaltic frequency result from the stretch effect on the ureter indigenous the arsenal of urine within the lumen. The second means of overcoming high vesical pressure is by summating contractions to produce a greater force with a much longer duration. This was evident in the dog experiments explained in the thing in which sometimes two or much more closely spaced activity potentials produced a summated muscular response of lengthy duration.


Submucosal fibrosis that the urinary bladder and lower ureters is responsible for many of the morbidity native urinary schistosomiasis. The bladder volume is typically reduced, leading to enhanced frequency that micturition. Much less often, bladder neck obstruction may bring about chronic urinary retention, which may be further complicated by vesicoureteric reflux. Involvement of the detrusor in the fibrotic process may result in motor abnormalities including hyperirritability or atony. Cystoscopic check (Figure 6) shows a pale and atrophic bladder mucosa, v which aggregations of calcified granulomata might be seen as ‘sandy patches.’ islands of relatively healthy mucosa might fold to form small cysts (‘cystitis cystica’) the may likewise involve the ureters (‘ureteritis cystica’). Radiological examination display screens bladder calcification as straight opacities follow me its wall, and also the reduced ureters and seminal motor (Figure 8) (Barsoum, 2010).


*

Figure 8. Radiological manifestations the urinary schistosomiasis. (a) linear bladder calcifications (Plain); (b) contract bladder with best Grade V vesicoureteric reflux, megaureter, hydronephrosis, and loss that renal parenchyma (ascending study); (c) irregular filling defect in the bladder due to a fungating malignant tumor (ascending study).

From Barsoum, R., 2005. Schistosomiasis. In: Davison, A., Cameron, J.S., Grunfeld, J.P., Ponticelli, C., Ritz, E., Winereals, C.G., Ypersele, C.V. (Eds.), Oxford Text-Book that Clinical Nephrology, 3rd ed. Oxford university press, brand-new York, pp. 1173–1184, v permission. Permission requested on 17 respectable 2013.

The lower 3rd of the ureters is concurrently involved, causing luminal narrowing and upstream obstruction. However, because the upper sections are spared, the ureters are able to respond to dilatation through hypertrophy of their muscle layers, enough to push the urine v the distal narrow segment. This compensatory system protects the kidney from backpressure in a considerable proportion of patients. However, if the obstruction is severe, or connected with far-reaching vesicoureteric reflux, hydronephrosis may occur at some point leading to renal failure. Fortunately, reflux is reasonably rare in this setting, being generally iatrogenic as a consequence of crucial or surgical dilatation (Barsoum, 2010).

Obstruction and reflux pave the means to second bacterial infection, an especially following instrumentation. This further complicates the bladder inflammation and also may be associated in the pathogenesis the malignancy (see later). Epidemic of obstructed kidneys may result in interstitial inflammation, scarring, and also rapid decline of function. Chronic bacterial infection is blamed because that the enhanced frequency of stone formation in this patients (Barsoum, 2010).


J. Groen, B.F.M. Blok, in Implantable Neuroprostheses because that Restoring Function, 2015

17.3.4 Nonobstructive chronic urinary retention

Nonobstructive chronic urinary retention is identified as a non-painful bladder through a chronic high postvoid residual: that is, through a chronic high volume that urine in ~ the end of micturition without urodynamic proof of anatomic obstruction (Abrams et al., 2002; Haylen et al., 2010; Siegel, 2005). No lower limit that the residual is specified in this definition. An ICS standardization report on terminology notes that a minimum that 300 mL has previously been pointed out (Abrams et al., 2002). A much more recent global Urogynecological Association/ICS share report ~ above the terminology for female pelvic floor dysfunction suggests a value of 200 mL (Haylen et al., 2010). The retention might be brought about by detrusor underactivity, in i beg your pardon the detrusor voiding contraction is of diminished strength or duration, or by one acontractile detrusor: that is, a detrusor the cannot be prove to contract throughout a urodynamic study. Alternatively, retention might be brought about by negative relaxation of the pelvic floor and also the striated urinary sphincter. A certain group the patients with this voiding dysfunction is written of women v Fowler syndrome. These space premenopausal women in whom electromyography the the sphincter using a concentric needle electrode reveals sound reminiscent that the underwater recordings that whales singing (Swinn, Kitchen, Goodwin, & Fowler, 2000). The FDA approved SNM because that the treatment of nonobstructive chronic retention in 1999.


BARRIE HOPSON, man HAYES, in The Theory and Practice that Vocational Guidance, 1968

IMPULSE HYPOTHESIS

This method has been stressed in specific by the psychoanalysts who emphasize the prestige of unconscious motivations in everyday life. Ernest Jones price quotes the instance of the child who proved an unnaturally strong interest in micturition who ended up being a renowned engineer the bridges and canals. We have all heard story of the sadist that becomes a surgeon or a butcher, and the homosexual that becomes a barber. Again, however, a few examples do not substantiate one all-embracing theory. Together the accident hypothesis characteristics all occupational an option to the responses the an separation, personal, instance to outside forces, so the impulse hypothesis stresses the all-importance of internal factors, the is, the emotionally forces. Numerous surgeons deserve to be displayed not come have had abnormal sadistic urges during childhood, and also all engineers connected in the construction of bridges and canals execute not exhibit childish fascination with micturition. Also, occupational choices other 보다 surgery room made by people with solid sadistic impulses, and even if this group of job were increased to encompass butchers, dentists, prison officers, etc., it would still be too narrow to incorporate all occupations permitting expression of therefore pervasive one impulse.

An attempt to instead of a more sophisticated strategy to the concern of “impulses” and also their effects on occupational an option has been made by “need theorists” prefer Anne Roe (Chapter 11) and psychoanalytic thinkers like Bordin, Segal and also Nachman (1963).

See more: What Is A 16 Sided Shape Called ? Name Of Geometric Shapes


DrDennis Fitzpatrick phd CEng BEng(Hons), in Implantable electronic Medical Devices, 2015

7.2 Detrusor Hyperreflexia

Detrusor hyperreflexia is a problem in which the bladder quiet functions but there is lose of voluntary regulate normally connected with neurological spinal cord lesions over the sacral cord segment such the the sacral reflex is intact and functioning however is no under greater center control. The bladder will still fill up v urine yet periodic involuntary contractions will cause the bladder come spontaneously empty. The micturition will not generally be complete, leave a tiny residual volume of urine in the bladder. However, if the relaxations that the outside sphincter are coordinated v the bladder wall contractions, bladder evacuation might be adequate, giving continence. If there is uncoordinated task of the outside sphincter through the bladder, known as detrusor–sphincter dyssynergia, press inside the bladder will certainly rise because of uncoordinated contractions of the exterior sphincter resulting in the bladder to empty frequently, top to active incontinence. This outcomes in a residual volume of to pee which have the right to be quite large and can frequently lead to increased risk of epidemic and possible kidney damage due to an increase in ago pressure effects.