Müller gang

Confluence of Müller's duct into the urogenital sinus in a female human embryo in the 8.5 to 9th week (from Gray's Anatomy )

The Müller duct (lat .: ductus paramesonephricus ) is - in addition to the urnal duct or Wolff duct (lat .: ductus mesonephricus ) - one of those embryonic systems of the genital organs that are present in both sexes and from the normal (female ) Sexual differentiation of the fallopian tubes , the uterus and the upper part of the vagina arise. It is named after Johannes Peter Müller, who first described it .

Indifferent stage

The Müller duct arises in the area of ​​the urogenital ridge as an elongated invagination of the coelom epithelium and thus from the mesoderm , runs parallel to the urinary duct and, like this, flows into the urogenital sinus (with the exception of the monotones , the urogenital sinus recedes in the course of further development other animals it remains as a cesspool ).

A. Before the embryonic differentiation, the gonads and the reproduction channel ( Wolff gear = blue and Mullerian gear = red ) as a result of the gene products of the Y chromosome , is carried out a differentiation to testis by means of the Anti-Mullerian Hormone , English Anti- Müllerian hormone (AMH) initiate the involution of the Müllerian Ganges. The development of Wolff's Ganges progresses through testosterone production. C. In the absence of testicular determinative factor , English testis determining factor (TDF) develop the ovaries and the Wolff transition degenerate, while the derivatives of the Müllerian duct unfold itself.

Male sexual differentiation

As part of male sexual differentiation, the Sertoli cells of the fetal testes produce the anti-Müllerian hormone (AMH). This is a proteohormone that causes the regression of the Müller ducts. Usually only the prostatic utriculus remains . If the hormone is missing or if its binding to the corresponding receptor is prevented, then, in addition to the development of typically male sexual characteristics, the structures that arise in female sexual differentiation from the Müller-gang also develop. This is known as Müller-Gang persistence syndrome.

Female sexual differentiation

Since female fetuses are consequently unable to produce AMH, they, on the contrary, lead to a further differentiation of the Müllerian duct, with estrogens of different origins being responsible for this further development. With them without AMH fallopian tubes ( tuba uterina ), uterus ( uterus ) and vagina ( vagina ) are formed.

At the beginning, the Müller Gang can be divided into three sections:

1. the cranial part that runs vertically,
2. the middle part, which crosses the urnal duct and pulls it across the middle of the body. These two parts are becoming both sides of the body cavity to the fallopian tubes, wherein the top portion with its opening in the coelomic cavity , the infundibulum will form the tube.
3. the lower part, again running vertically, which will unite with its counterpart - which is drawn from the other side of the body into the middle of the body - and will ultimately form the uterus and the upper part of the vagina . This also explains why men with a Müller-Gang persistence syndrome are completely inconspicuous in terms of their outward appearance.

Developmental disorders

So-called Müllerian duct anomalies - or, more correctly, “disorders of the fusion of the lower part of the Müller duct ” - are the cause of many malformations of the uterus such as the uterus duplex , the uterus bicornis , the cervical atresia and other anomalies.

A segmental agenesis can be the starting point for cysts.

See also

• Anti-Müllerian hormone

Web links

http://www.embryology.ch/allemand/ugenital/genitinterne02.html

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !