The following are derivatives of Paramesonephric duct except:
Ans. B. Ovary. (Ref. Langman's medical embryology pg. 360; Fig. 14.24).The ovary is formed mainly from the genital ridge and partly from the mesonephros. Fallopian tubes, Uterus, Cervix and Upper vagina develop from paramesonephric (Mullerian) duct." At first both the male and the female have 2 pairs of genital or sex ducts:# Mesonephric (Wolffian - medial) and- The mesonephric ducts in the female degenerate except for remnants like epoporon and paraphoron, which develop from them.- The mesonephric ducts develop into the main genital ducts of the male# Paramesonephric (Mullerian - lateral) ducts.- The paramesonephric ducts in the male degenerate except for a small portion at their cranial ends, the appendix/ hydatid testis and prostate utricle.- The paramesonephric ducts develop into the main genital ducts of the female."Origin of genital structures Embryological partAdult Female derivativesAdult Male derivativesAGonadsOvary, follicles, rete ovariiTestes, Seminiferous tubules, Rete testesBParamesonephric ductsUterine tubes, Uterus, Cervix and Upper part of vaginaAppendix of testes, Prostatic utricleCMesonephric (Wolffian) ductsGartner's DuctSeminal vesicles, Epididymis, Ejaculatory duct, Ductus deferens. Pnemonic: SEEDDPhallusClitorisGians and body of penisEUrogenital foldsLabia minoraVentral aspect of penisFLabioscrotal swellingsLabia majoraScrotumEducational points:# Sertoli cells then produce mullerian inhibiting substance (MIS, also called antimullerian hormone, AMH) that causes regression of the paramesonephric (mullerian) ducts.# Leydig cells produce testosterone, which enters cells of target tissues where it may remain or be converted to dihydrotestosterone by a 5 a reductase enzyme.- Blood testis barrier is formed by sertoli cells (Germ cells do not contribute to the barrier).- Bicornuate uterus: Results from incomplete fusion of the paramesonephric ducts (vs. complete failure of fusion, resulting in double uterus and vagina).- Duplications of the uterus result from lack of fusion of the paramesonephric ducts in a local area or throughout their normal line of fusion.* In its extreme form the uterus is entirely double (uterus didelphys);e* In the least severe form, it is only slightly indented in the middle (arcuate uterus).* One common anomaly is uterus bicornis (uterus has two horns entering a common vagina).
Uterus
Ovary
Fallopian tube
Upper vagina
Urogenital System