Prostatic utricle

Overview
The prostatic utricle (Latin for "pouch of the prostate") is a small indentation located in the prostatic urethra, at the apex of the urethral crest, on the seminal colliculus, laterally flanked by openings of the ejaculatory ducts. It is also known as the vagina masculina.

It is often described as "blind," meaning that it is a duct that does not lead to any other structures.

It can sometimes be enlarged.

Embryology
It may serve no function. However, in "A Practical treatise on sexual disorders of the male and female" 3rd ed. By Robert William Taylor, it states "in coitus it so contracts that it draws upon the openings of the ejaculatory ducts, and thus renders them so patulous that the semen readily passes through."

It is important primarily because it is the male homologue of the female uterus and vagina, usually described as derived from the Müllerian ducts, though this is occasionally disputed. (See List of homologues of the human reproductive system for more details.) The paramesonephric (Mullerian) duct obliterates in the male, forming the prostatic utricle and in the female becomes the fallopian tube and uterus.