My watch list

Urogenital sinus

Urogenital sinus

Urogenital sinus of female human embryo of eight and a half to nine weeks old. (Urogenital sinus labeled at bottom.)

Stages in the development of the external sexual organs in the male and female. ("Opening of urogenital sinus" labeled in diagram D.)
Latin	sinus urogenitalis
Gray's	subject #252 1213
Carnegie stage	15
Precursor	Cloaca
Gives rise to	urethra, bladder, vagina
Dorlands/Elsevier	s_12/12739359

The urogenital sinus (also known as the persistent cloaca) is a part of the human body only present in the development of the urinary and reproductive organs. It is the ventral part of the cloaca, formed after the cloaca separates from the rectum. It eventually becomes, among other things, the bladder.

Additional recommended knowledge

How to quickly check pipettes?

Daily Visual Balance Check

Weighing the right way

Pathology

A urogenital sinus anomaly is also a rare birth defect in women where the urethra and vagina both open into a common channel.

Additional images

v • d • e Prenatal development/mammalian embryogenesis - Development of the urinary and reproductive organs
General Urinary/Reproductive system	Cloacal membrane - Cloaca - Urethral groove - Urogenital sinus - Urachus - Urogenital folds
Kidney development	Nephrogenic cord - Nephrotome - Pronephros - Mesonephros (Mesonephric tubules) Ureteric bud - Metanephric blastema
Fetal genital development - primarily internal	Gonadal ridge - Sex cord (Cortical cords, Testis cords) Pronephric duct/Wolffian duct/mesonephric duct - Müllerian duct/paramesonephric ducts (Vaginal plate)
Primarily external	Genital tubercle - Phallus - Labioscrotal folds Gubernaculum - Processus vaginalis
see also list of homologues of the human reproductive system