Urethral sphincters
The urethral sphincters are two muscles used to control the exit of urine in the urinary bladder through the urethra.The external urethral sphincter originates at the ischiopubic ramus and inserts into the intermeshing muscle fibers from the other side.In males and females, both internal and external urethral sphincters function to prevent the release of urine.The internal urethral sphincter controls involuntary urine flow from the bladder to the urethra, whereas the external urethral sphincter controls voluntary urine flow from the bladder to the urethra.[5] The urethral sphincter is considered an integral part of maintaining urinary continence, and it is important to understand its role in some conditions: This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)
musclesurinary bladderurethrafemale external urethral sphincterinternal urethral sphincterischiopubic ramuspudendal nerveinternal sphincter muscle of urethradetrusorsmooth muscleinvoluntaryautonomicurinationfemalemale external sphincter muscle of urethradeep perineal pouchmembranous urethraskeletal muscleExternal sphincter muscle of male urethraExternal sphincter muscle of female urethrainternalurinary incontinenceejaculationinferior pubic ramusvaginoplastyurinary continenceStress urinary incontinenceprostatectomyNeurogenic bladder dysfunctionUrge incontinenceRetrograde ejaculationArtificial urinary sphincterUniversity of Pittsburghpublic domainGray's Anatomyurinary systemKidneysFasciaCapsuleCortexcolumnMedullapyramidsmedullary interstitiumCortical lobuleMedullary rayNephronCirculationRenal arterysegmentalinterlobararcuateinterlobularafferentRenal veinPeritubular capillariesVasa rectaefferentRenal corpuscleGlomerulusBowman's capsuleGlomerular basement membranePodocyteFiltration slitsMesangiumIntraglomerular mesangial cellRenal tubuleProximal convoluted tubuleLoop of HenleDescendingThin ascendingThick ascendingDistal convoluted tubuleCollecting duct systemConnecting tubulePapillary ductTubular fluidRenal papillaMinor calyxMajor calyxRenal pelvisJuxtaglomerular apparatusMacula densaJuxtaglomerular cellsExtraglomerular mesangial cellUretersUreteropelvic junctionBladderVesical arteriesVesical veinsVaginal arteryDetrusor muscleMedian umbilical ligamentTrigoneInternal urethral orificepre-prostaticprostaticintermediatespongynavicular fossaLacunae of Morgagniurethral glandUrinary meatusperineumAnal triangleExternalIschioanal fossaPudendal canalUrogenital triangleSuperficial perineal pouchSuperficial transverse perinealBulbospongiosusIschiocavernosusDeep transverse perinealSuperficial perineal fasciaColles' fasciaDartos fasciaDeep perineal fascia / superficial investing fascia (Gallaudet's)Deep fascia of the penis (Buck's)Urogenital diaphragmInferior fascia (Perineal membrane)Superior fasciaPelvic diaphragmInferior fascia