Urogenital sinuses

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

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.

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

Enlarged view from the front of the left Wolffian body before the establishment of the distinction of sex.

External links

• Urologyhealth.org page on Urogenital Sinus anomalies
• Fetal pig dissection