Internal urethral orifice explained

Internal urethral orifice
Latin:	ostium urethrae internum

The internal urethral orifice is the opening of the urinary bladder into the urethra.^[1]

Anatomy

It is usually somewhat crescent-shaped.

Relations

It is formed by the neck of the urinary bladder. It opens at the apex/inferior angle of the trigone of the bladder, some 2-3 cm anteromedial to either ureteral orifice.

The mucous membrane immediately posterior to it presents a slight elevation in males - the uvula vesicae - caused by the middle lobe of the prostate.

See also

• Internal sphincter muscle of urethra

External links

• - "The Male Pelvis: The Urethra"

Notes and References

1. Web site: orifice interne de l'urèthre l.m. - Dictionnaire médical de l'Académie de Médecine . 2024-06-01 . www.academie-medecine.fr.