View source for Mesonephros

{{Infobox Embryology |
  Name          = {{PAGENAME}} |
  Latin         = |
  GraySubject   = 252 |
  GrayPage      = 1205|
  Image         = Gray986.png |
  Caption       = Reconstruction of a human [[embryo]] of 17 mm. (Label for Mesonephros is at center right.) |
  Image2        = |
  Caption2      = |
  System        = |
  CarnegieStage = 14 |
  Precursor     = [[intermediate mesoderm]] |
  GivesRiseTo   = |
  MeshName      = Mesonephros |
  MeshNumber    = A16.254.500 |
  DorlandsPre   = m_11 |
  DorlandsSuf   = 12527308 |
}}
{{SI}}
{{CMG}}



==Overview==

The '''mesonephros''' (Latin for "middle [[kidney]]") is one of three [[excretory system|excretory organs]] that develop in [[vertebrate]]s. It serves as the main excretory organ of aquatic vertebrates and as a temporary kidney in higher vertebrates. The mesonephros is included in the '''Wolffian body''' after [[Caspar Friedrich Wolff]] who described it in 1759. (The Wolffian body is composed of : mesonephros + paramesonephrotic blastema)

==Structure==
The mesonephros is composed of the [[mesonephric duct]] (also called the Wolffian duct), [[mesonephric tubules]], and associated capillary tufts. A single tubule and its associated capillary tuft is called a ''mesonephric excretory unit''; these units are similar in structure and function to [[nephron]]s of the adult kidney. The mesonephros is derived from [[intermediate mesoderm]] in the vertebrate embryo.

==Differences between males and females==
In human males, the mesonephros gives rise to the [[efferent ductules]] of the [[testis]], the [[epididymis]], [[vas deferens]], [[seminal vesicle]], and vestigial structures such as the [[appendix testis]], [[appendix epididymis]], and [[paradidymis]]. 

The mesonephros largely regresses in human females, though vestigial structures such as [[Gartner's cyst]]s, the [[epoophoron]], and [[paroophoron]] are common.

==Differences among species==
The mesonephros persists and form the permanent kidneys in fishes and amphibians, but in reptiles, birds, and mammals, it atrophies and for the most part disappears rapidly as the permanent kidney ([[metanephros]]) develops begins during the sixth or seventh week, so that by the beginning of the fifth month only the ducts and a few of the tubules of the mesonephros remain.

==Additional images==
<gallery>
 Image:Gray1108.png|Broad ligament of adult, showing epoöphoron. 
</gallery>

== See also ==
* [[pronephros]]
* [[metanephros]]
* [[paramesonephric ducts]], ducts beside (para-) the mesonephros

{{Development of urinary and reproductive systems}}


[[Category:Embryology]]
[[Category:Kidney]]

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