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Reproductive Embryology - Pathology (view source)
Revision as of 18:51, 8 August 2009
, 18:51, 8 August 2009no edit summary
==EMBRYOLOGICAL DEVELOPMENT OF THE GENITAL TRACT==
==EMBRYOLOGICAL DEVELOPMENT OF THE GENITAL TRACT==
===Early embryo====
===Early embryo===
Small indifferent gonads. The primitive structures which will become gonads and genital tract are identical at this stage.
Small indifferent gonads. The primitive structures which will become gonads and genital tract are identical at this stage.
Paired mesonephric ducts (Wolffian) or paramesonephric (Mullerian) ducts fuse caudally with urogenital sinus.
Paired mesonephric ducts (Wolffian) or paramesonephric (Mullerian) ducts fuse caudally with urogenital sinus.
#Testicular feminisation: XY genotype with testosterone producing but sterile gonads internally and female external genitalia. The vagina is blind-ending with absence of internal genital tract. These male pseudohermaphrodites exhibit male behaviour and have significant testosterone levels.
#Testicular feminisation: XY genotype with testosterone producing but sterile gonads internally and female external genitalia. The vagina is blind-ending with absence of internal genital tract. These male pseudohermaphrodites exhibit male behaviour and have significant testosterone levels.
===FREEMARTIN SYNDROME (i.e. Chimeras)==='''
A freemartin is a masculinised female born co-twin with a normal male. 11/12 female calves born co-twin to a male will be freemartins. The condition is mainly recognised in cattle, but occurs in sheep, goats and pigs.
A freemartin is a masculinised female born co-twin with a normal male. 11/12 female calves born co-twin to a male will be freemartins. The condition is mainly recognised in cattle, but occurs in sheep, goats and pigs.
<Br>During foetal development placental anastomosis allows blood to be shared by the twins (anastamosis occurs in 90% of bovine twins, <2% in other species).Each twin acquires genetically distinct population of blood cells from the other twin - CHIMERISM.
<Br>During foetal development placental anastomosis allows blood to be shared by the twins (anastamosis occurs in 90% of bovine twins, <2% in other species).Each twin acquires genetically distinct population of blood cells from the other twin - CHIMERISM.