Blakiston's Medical Dictionary (which I bought and have held since 1964) gives the following definition.
An epithelial tube or cord connecting the apex of the bladder with the allantois, regarded as the stalk of the allantois or as the degenerative apex of the primative bladder. Its connective tissue forms the medial umbilical ligament.
Now, if that doesn't satisfy, it continues to say:
patent urachus - A condition in which the urachus of the embryo does not become obliterated, but persists as a tube from the apex of the bladder to the umbilicus.
Hope this helps you somewhat. (Mind, umbilicus = belly button).
bye.dub
(absolutely no position at all - checking my b.b. though!)
