Editing Urethra (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 middle part forming the urethra; the upper part is largest and becomes the [[urinary bladder]], and the lower part then changes depending on the biological sex of the embryo.<ref name=Langman2019 /> The cells lining the urethra (the epithelium) come from [[endoderm]], whereas the connective tissue and smooth [[muscle]] parts are derived from [[mesoderm]].<ref name=Langman2019 />

After the third month, urethra also contributes to the development of associated structures depending on the biological sex of the embryo. In the male, the epithelium multiples to form the [[prostate]]. In the female, the upper part of the urethra forms the urethra and [[paraurethral gland]]s.<ref name=Langman2019 />