Urinary bladder 32259 222146493 2008-06-27T19:54:10Z Arcadian 104523 split out [[Urinary bladder disease]] {{This|the urinary bladder|Bladder (disambiguation)}} {{Infobox Anatomy | Name = Urinary bladder | Latin = vesica urinaria | GraySubject = 255 | GrayPage = 1227 | Image = Illu urinary system.jpg | Caption = Urinary system. | Image2 = Illu_bladder.jpg | Caption2 = Bladder | Width = 300 | System = | Artery = [[Superior vesical artery]]<BR>[[Inferior vesical artery]]<BR>[[Umbilical artery]]<BR>[[Vaginal artery]] | Vein = [[Vesical venous plexus]] | Nerve = [[Vesical nervous plexus]] | Lymph = [[external iliac lymph nodes]], [[internal iliac lymph nodes]] | Precursor = [[urogenital sinus]] | MeshName = Bladder | MeshNumber = A05.810.161 | DorlandsPre = v_07 | DorlandsSuf = 12855244 | }} In [[anatomy]], the '''urinary bladder''' is a hollow, [[muscle|muscular]], and distensible (or elastic) organ that sits on the [[pelvic floor]] in [[mammal]]s. It is the organ that collects [[urine]] excreted by the [[kidney]]s prior to disposal by [[urination]]. Urine enters the bladder via the [[ureter]]s and exits via the [[urethra]]. In males, the bladder is superior to the [[prostate]], and separated from the [[rectum]] by the [[rectovesical excavation]]. In females, the bladder is separated from the [[uterus]] by the [[vesicouterine excavation]]. == Detrusor muscle == The detrusor muscle is a layer of the urinary bladder wall made of [[smooth muscle]] [[muscle_fibers|fibers]] arranged in spiral, longitudinal, and circular [[Fiber_bundle|bundles]]. When the bladder is stretched, this signals the [[parasympathetic]] nervous system to contract the [[detrusor muscle]]. This encourages the bladder to expel [[urine]] through the [[urethra]]. For the urine to exit the bladder, both the [[autonomic]]ally controlled internal [[sphincter]] and the [[somatic|voluntarily]] controlled external sphincter must be opened. Problems with these muscles can lead to [[Urinary incontinence|incontinence]]. If the amount of urine reaches 100% of the urinary bladder volume, the voluntary sphincter becomes involuntary and the urine will be ejected instantly. The body cannot afford having the urinary bladder burst. The urinary bladder usually holds 400–620 mL of urine, but it can hold twice this without rupturing if, for example, the outflow is obstructed. The desire to [[Urination|urinate]] usually starts when the bladder reaches around 75% of its working volume. If the subject is distracted the desire can fade and return with more urgency as the bladder continues to fill. Since the urinary bladder has a [[transitional epithelium]], compared to the intestine mucosa, the urinary bladder does not produce mucus. <ref> [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WKP-4PMK2X4-Y&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=89f27dee46151805e831331aace3a19f T . Chin , C . Liu , H . Tsai , C . Wei. Vaginal reconstruction using urinary bladder flap in a patient with cloacal malformation] </ref> ==Fundus== <!--Fundus of the bladder redirects here--> The fundus of the urinary bladder is the superior surface of the bladder. It is [[lymphatically]] drained by the [[external iliac lymph nodes]]. The peritoneum lies superior to the fundus. ==References== {{reflist}} ==See also== * [[Artificial bladder]] * [[Bladder cancer]] * [[Bladder spasm]] * [[Bladder sphincter dyssynergia]], a condition in which the sufferer cannot coordinate relaxation of the urethra sphincter with the contraction of the bladder muscles * [[Cystitis]] * [[Hematuria]], or presence of blood in the urine, is a reason to seek medical attention without delay, as it is a symptom of bladder cancer as well as bladder and [[kidney stone]]s. * [[Neurogenic bladder]] * [[Ureterocele]] * [[Urinary incontinence]] * [[Urodynamics]] The study of the functional aspects of the detrusor muscle. * [[Uvula of urinary bladder]] * [[Vesicouretic reflux]] * [[Urinary bladder disease]] ==External links== * {{KansasHistology|epithel|epith09}} "Urinary Bladder" * {{UCDavisOrganology|Urinary/mammal/bladder/bladder1}} - "Mammal, bladder (LM, Medium)" * {{IowaHistologyInteractive|445}} * {{SUNYAnatomyLabs|43|07|01|00}} - "The Female Pelvis: The Urinary bladder" * {{SUNYAnatomyLabs|44|04|01|03}} - "The Male Pelvis: The Urinary bladder" ==Additional images== <gallery> Image:Illu penis.jpg|Structure of the penis Image:Illu repdt female.jpg|Organs of the female reproductive system. Image:Gray402.png|Coronal section of pelvis, showing arrangement of fasciæ. Viewed from behind. Image:Gray829.png|Dissection of side wall of pelvis showing sacral and pudendal plexuses. (Bladder visible at lower left.) | Image:Gray1037.png|The peritoneum of the male pelvis. Image:Gray1135.png|Median sagitta section of male pelvis. Image:Gray1136.png|Male pelvic organs seen from right side. Image:Gray1139.png|Median sagittal section of female pelvis. Image:Gray1140.png|The interior of bladder. Image:Gray1141.png|Vertical section of bladder wall. Image:Gray1152.png|Fundus of the bladder with the vesiculæ seminales. Image:Gray1156.png|Vertical section of bladder, penis, and urethra. Image:Gray1165.png|Female pelvis and its contents, seen from above and in front. Image:Gray1224.png|Topography of thoracic and abdominal viscera. Image:Penis.svg|The bladder can be seen highlighted in yellow in the illustration. Image:Urinary bladder.JPG|Layers of the urinary bladder wall and cross section of the detrusor muscle. </gallery> {{urinary system}} [[Category:Pelvis]] [[Category:Organs]] [[Category:Urology]] [[Category:Urinary system]] {{Link FA|de}} [[ay:Yaq'allachi]] [[bg:Пикочен мехур]] [[ca:Bufeta urinària]] [[cs:Močový měchýř]] [[cy:Pledren]] [[da:Urinblære]] [[de:Harnblase]] [[es:Vejiga urinaria]] [[fr:Vessie]] [[hr:Mokraćni mjehur]] [[ko:방광]] [[id:Kandung kemih]] [[it:Vescica urinaria]] [[he:שלפוחית השתן]] [[la:Vesica]] [[lt:Šlapimo pūslė]] [[nl:Urineblaas]] [[ja:膀胱]] [[no:Urinblære]] [[pl:Pęcherz moczowy]] [[pt:Bexiga]] [[qu:Ispay puru]] [[ru:Мочевой пузырь]] [[sk:Močový mechúr]] [[sl:Sečni mehur]] [[fi:Virtsarakko]] [[th:กระเพาะปัสสาวะ]] [[tr:İdrar kesesi]] [[yi:בלעדער]] [[zh:膀胱]]