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Discussion Starter · #1 ·
a human fetus with 46, XY genotype has testis with normally functioning leydig cells but total abscence of sartoli cells which of the following phenotype is most likely to develop?


A) male internal & external genitalia
B) female internal & external genitalia
C) female internal genitalia & male external genitalia
D) male internal genitalia & female external genitalia
E) both male & female internal genitalia & male external genitalia
F) male internal genitalia & both female & male external genitalia
 

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"-" Sertoli cells --> "-" Mullerian inhibiting factor --> development of internal femal: paramesonephric duct or fallopian tube, uterus, upper 1/3 of vagina

Leydig cells --> androgens --> mesonephric duct or male internal: seminal vesicles, epididymis, ejaculatory duct, ductus deferens.

So we'll have:
1. male internal
2. female internal, no MIF
3. male external , testosteron and DHT

So --> choice E.
 

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Discussion Starter · #5 ·
E

ya u got it correct...
46 XY genotype... SRY gene on Y chromosome code for TDF(testis determining factor).....that causes differentiation of primitive genital ridge to testis....
now we hv testis with its sartoli cells n leydig cells....
sartoli cells release MIF (mullerian inhibiting factor) that inhibit paramesonephric duct from which female internal genitalia r derived but unfortunately....this pt is lacking it...so it will hv female internal genitalia..
from leydig cells...testosterone releases....that develops male internal genitalia.....testosterone converted to DHT thet will develop male external genitalia....
so we r left with both male & female internal genitalia & male external genitalia
:)
 

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if MIF is absent , only mullerian duct will develop and only female internal are seen isnt it ???? i didnt get how both male and female internal present ??
 

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Discussion Starter · #7 ·
if MIF is absent , only mullerian duct will develop and only female internal are seen isnt it ???? i didnt get how both male and female internal present ??
female internal genitalia develop from paramesonephric ducts which r inhibited by MIF...n male internal genitalia develop from mesonephric duct...both r not derived from same structure...so if MIF is not der..paramesonephric n mesonephric both will develop.....got it???:)
 

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questions and materials on abdomen, thorax, upperlimb; renal and respiratory physiology,

these are areas which I just re-treated. I would be very grateful if I can get posts (materials and questions on the topics above)
 
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