Editing Bladder (section)

===Development===
{{Further|Development of the urinary system}}
In the developing [[embryo]], at the hind end lies a [[Cloaca (embryology)|cloaca]]. This, over the fourth to the seventh week, divides into a [[urogenital sinus]] and the beginnings of the [[anal canal]], with a wall forming between these two inpouchings called the [[urorectal septum]].<ref name=Langman2019>{{cite book |last1=Sadley |first1=TW |title=Langman's medical embryology |date=2019|location=Philadelphia|publisher=Wolters Kluwer |isbn=9781496383907 |edition=14th|section=Bladder and urethra|pages=263–66}}</ref> The urogenital sinus divides into three parts, with the upper and largest part becoming the bladder; the middle part becoming the [[urethra]], and the lower part changes depending on the biological sex of the embryo.<ref name=Langman2019 />

The human bladder derives from the [[urogenital sinus]], and it is initially continuous with the [[allantois]]. The upper and lower parts of the bladder develop separately and join around the middle part of [[prenatal development|development]].<ref name="Viana"/> At this time the ureters move from the [[mesonephric duct]]s to the trigone.<ref name="Viana"/> In males, the base of the bladder lies between the rectum and the pubic symphysis. It is superior to the [[prostate]], and separated from the [[rectum]] by the [[recto-vesical pouch]]. In females, the bladder sits inferior to the uterus and anterior to the vagina; thus its maximum capacity is lower than in males. It is separated from the [[uterus]] by the [[vesico-uterine pouch]]. In [[infants]] and young children the urinary bladder is in the [[abdomen]] even when empty.<ref>{{cite book |author1= Moore, Keith L. |author2= Dalley, Arthur F |title= Clinically Oriented Anatomy|url= https://archive.org/details/clinicallyorient00moor_1 |url-access= registration |edition= 5th |year= 2006 |publisher= Lippincott Williams & Wilkins |isbn= 9780781736398 }}</ref>