Mesonephric duct

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Mesonephric duct
Gray1109.png
Urogenital sinus of female human embryo of eight and a half to nine weeks old.
Details
Carnegie stage11
Days28
Precursorintermediate mesoderm
Gives rise tovas deferens, seminal vesicles, epididymis
Identifiers
Latinductus mesonephricus; ductus Wolffi
MeSHD014928
TEduct_by_E5.6.2.0.0.0.4 E5.6.2.0.0.0.4
Anatomical terminology

The mesonephric duct (also known as the Wolffian duct, archinephric duct, Leydig's duct or nephric duct) is a paired organ that forms during the embryonic development of humans and other mammals and gives rise to male reproductive organs.

Structure[edit]

The mesonephric duct connects the primitive kidney, the mesonephros, to the cloaca. It also serves as the primordium for male urogenital structures including the epididymis, vas deferens, and seminal vesicles.

Development[edit]

In both male and female the mesonephric duct develops into the trigone of urinary bladder, a part of the bladder wall, but the sexes differentiate in other ways during development of the urinary and reproductive organs.

Male[edit]

In a male, it develops into a system of connected organs between the efferent ducts of the testis and the prostate, namely the epididymis, the vas deferens, and the seminal vesicle. The prostate forms from the urogenital sinus and the efferent ducts form from the mesonephric tubules.

For this it is critical that the ducts are exposed to testosterone during embryogenesis. Testosterone binds to and activates androgen receptor, affecting intracellular signals and modifying the expression of numerous genes.[1]

In the mature male, the function of this system is to store and mature sperm, and provide accessory semen fluid.

Female[edit]

In the female, with the absence of anti-Müllerian hormone secretion by the Sertoli cells and subsequent Müllerian apoptosis, the mesonephric duct regresses, although inclusions may persist. The epoophoron and Skene's glands may be present. Also, lateral to the wall of the vagina a Gartner's duct or cyst could develop as a remnant.

Function[edit]

Sexual differentiation[edit]

History[edit]

It is named after Caspar Friedrich Wolff who described the mesonephros and its ducts in his dissertation in 1759.[2]

Additional images[edit]

Diagrams to illustrate the changes in the cloaca in mammals during development. A, early embryonic stage, showing the cloaca receiving the urinary bladder, the rectum, and the Wolffian duct, as in the lower vertebrates. B, later stage, showing the beginning of the fold which divides the cloaca into a ventral urogenital sinus which receives the urinary bladder, Wolffian ducts, and ureters, and into a dorsal part which receives the rectum. C, further progress of the fold, dividing the cloaca into urogenital sinus and rectum; the ureter has separated from the Wolffian duct and is shifting anteriorly. D, completion of the fold, showing complete separation of the cloaca into ventral urogenital sinus and dorsal rectum.

See also[edit]

References[edit]

  1. ^ Hannema SE, Print CG, Charnock-Jones DS, Coleman N, Hughes IA (2006). "Changes in gene expression during Wolffian duct development". Horm. Res. 65 (4): 200–9. doi:10.1159/000092408. PMID 16567946. S2CID 2444520.
  2. ^ synd/2845 at Who Named It?

External links[edit]