The primary urethral groove or urethral groove is a temporary linear indentation on the underside (ventral side) of the male
penis
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...
during embryonic development.
In humans, it typically appears around 8 weeks of gestation and becomes closed into a normal
male urethra
The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra con ...
by the 12th week.
Clinical significance
Failure of complete closure can be associated with
hypospadias
Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location in the head of the penis. It is the second-most common birth abnormality of the male reproductive system, affecting abou ...
.
References
{{DEFAULTSORT:Urethral Groove
Embryology of urogenital system
Human penis