The vaginal process (or processus vaginalis) is an
embryo
An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...
nic developmental outpouching of the
parietal peritoneum
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesothe ...
. It is present from around the 12th week of gestation, and commences as a peritoneal outpouching.
Sex differences
In males, it precedes the
testes
A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of androgens, primarily testosterone.
The ...
in their descent down within the
gubernaculum, and closes. This closure (also called ''fusion'') occurs at any point from a few weeks before birth, to a few weeks after birth. The remaining portion around the testes becomes the
tunica vaginalis
The tunica vaginalis is a pouch of serous membrane within the scrotum that lines the testis and epididymis (visceral layer of tunica vaginalis), and the inner surface of the scrotum (parietal layer of tunica vaginalis). It is the outermost of ...
.
If it does not close in females, it forms the
canal of Nuck
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The canal of Nuck, first described by Anton Nuck ( de) in 1691, is an abnormal patent (open) pouch of peritoneum extending into the labia majora of women. It is analogous to a patent processus vaginalis in males (see hydrocele testis, i ...
.
Clinical significance
Failure of closure of the vaginal process leads to the propensity to develop a number of abnormalities. Peritoneal fluid can travel down a patent vaginal process leading to the formation of a
hydrocele
A hydrocele is an accumulation of serous fluid in a body cavity. A hydrocele testis, the most common form of hydrocele, is the accumulation of fluids around a testicle. It is often caused by fluid collecting within a layer wrapped around the tes ...
. Persistent patent processus vaginalis is more common on the right than the left. Accumulation of blood in a persistent processus vaginalis could result in a
hematocele.
There is the potential for an indirect
inguinal hernia
An inguinal hernia or groin hernia is a hernia (protrusion) of abdominal cavity contents through the inguinal canal. Symptoms, which may include pain or discomfort especially with or following coughing, exercise, or bowel movements, are absen ...
to develop, although not all people with a patent vaginal process will develop one. The more patent the vaginal process, the more likely the patient is to develop a hernia. Congenital malformation of the vaginal process is also the leading cause of
testicular torsion, since lack of attachment to the inner lining of the scrotum leaves the testicles free to twist.
See also
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Canal of Nuck
__NOTOC__
The canal of Nuck, first described by Anton Nuck ( de) in 1691, is an abnormal patent (open) pouch of peritoneum extending into the labia majora of women. It is analogous to a patent processus vaginalis in males (see hydrocele testis, i ...
*
List of homologues of the human reproductive system
References
External links
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{{Development of urinary and reproductive systems
Embryology of urogenital system