Embryology
EMBRYOLOGY OF MALE REPRODUCTIVE SYSTEM
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- The urogenital system is formed mainly from mesodermal tissue that in early embryonic life forms the nephric and genital regions.
Primary medullary cords are characteristic of the early male gonad.
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These testis cords of primitive germ cells and supportive sertoli cells remain solid until just before puberty.When the seminiferous tubules are formed and they join the rete testis by means of tubuli recti.
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The rete testis in turn enters the efferent tubules, epididymis and ductus deferens that are formed from the mesonephric tubules and duct.
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Certain tubules of the mesonephros that do not form the testicular duct system may remain as small remnants called the ductuli aberrants and appendix testis near the head of t epididymis and the paradidymis near the body or tail of the epididymis
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During the middle trimester of gestation, the interstitial or Leydig cells are numerous especially in the equine fetus.
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In the very early fetal period, the external genitalia in the cloacae region are also in the indifferent stage characterized by a genital tubercle which elongates to form the phallus or penis with two genital folds that form the urethra and the two genital swellings that form the scrotum.
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Development of the external genitalia in males is hormonally controlled by androgens presumably from the fetal gonad.
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Undifferentiated genital structures in the embryo and their adult male counterparts
EMBRYONIC STRUCTURE
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ADULT
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Gonad
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Testis
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Mesentry
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Mesorchium
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Gubernaculum
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Ligamentum testis
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Paramesonephric duct or mullerian duct
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Appendix testis and uterus masculinus
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Mesonephric duct or wolffian duct and body
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Efferent tubules, epididymis, vas deferens , ampulla
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Genital tubercle
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Penis
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Genital folds
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Penile urethra
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Genital swelling
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Scrotum
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Last modified: Monday, 4 June 2012, 9:00 AM