sexual differenetiation Flashcards
how many chromosomes do gametes have
23
primary reproductive organs that generate gametes
gonads
delivers the gametes
reproductive tract
what supports gametes and intercourse
accessory sex glands that primarily produce secretions
what is the first time we have genetically unique individual 2n=46 chromosomes
conception
what dictates what the genetic sex- sexual determination- of the embryo
what chromosome the sperm delivers. sperm can deliver either x or y and female always give x
when does the embryonic window for sex specification start
at 6 weeks of gestation out of 38
karyotypes
chromosome spreads
what is true about the sexuality of the early human embryo
it is not sexually specified. from conception to 6 wks, the embryo is internally and externally identical in terms of reproductive systems
what is true about the sexuality of the early human embryo
it is not sexually specified. from conception to 6 wks, the embryo is internally and externally identical in terms of reproductive systems
early embryonic gonad is unspecified and undiferentiated and bipotential- wiating for signals
female reproductive tract
mullerian
male reproductive tract
wollfian
what tracts are present in the female and the male reproductiev tracts
both mullerian and wolffian reproductive tracts
what dictates gonadal sex
genetic sex
what establishes male gonadal sex
SRY transcription factor in chromosome Y
when do the male gonads established
at 7 weeks
what happens in the absence of the SRY transcription factor
a different signalling pattern ensues to determine the female gonadal sex
what is established when the SRY transcription factor is working or not
gonadal sex: testes or ovaries
when are internal reproduvtive tracts differentiated
after gonads are differentiated
what signals wolffian duct development
MIF (AMH) and androgens
what permits mullerina duct developent
absense of androgen and MIF (AMH)
what kind of hormone is MIG
protein hormone
what is testosterone converted to
dihydrotestosterone
what does MIF stand for and what does it do
mullerian inhibiting factor- degererates mullerian ducts
what leads to the degenerations of the wolffian ducts
absense of testosterone
what promotes the developement of undifferntiated external genetalia along male lines such as penis and scrotum
dihydrotestosterone
what transforms wolffian ducts into male reproductive tract such as epididymus, ducts deferense, ejaculatory ducts, seminal vesicles
testosterone
what is phenotypic sex determined by
presense or absense of masculinizing hormones
what leads to the development of mullerian ducts into female reproductive tract such as oviducts or uterus
absense of MIF
what leads to the development of undifferentiated external genitalia along female lines such as clitoris and labia
absense of testosterone
what are some androgens
testosteone, dihydrotestosteone, MIF/AMH
what supports the develpment of male reproductive tract and external male genitalia
androgens
what does AMH stand for
antimullerian hormone
when are external genitalia didfferentiated
after gonads
when is sex specific hormone profiles made
7-9 weeks
when is phenotypic sex present
differentiation of external genitalia evident by 10-12 weeks
what continues until birth
maturation of sex specific reproductive tract and ecternal genitalia
what are the 3 embryological things that make up undifferentiated genitalia
genital tubercle
urethral folds
genital swellings
what happens to the ovaries and the testes
ovaries remain in the abdominal cavity, testes descent into the scrotum
what causes the testes to descend into the scrotum
androgens
GUB
gubernaculum
when do the testes descend
97% newborns have it and remainder 3% within 3 months after birth
when do disorfers of sexual differentiation occur
when the signals are insufficient, absent or in excess
what happnes when the SRY or TDF signalling is absent in male embryo
female developemnt (ovaries, tract, genitalia)
what happens when there is absent androgen receptor in male embryo
male testes, female physical apprearance with breast develpemnt
what happens when there is insufficient testosterone to DHT conversion in male embryo
male tesetes and reproductive tract, famale external genitalai
what happens when there is exessive androgen production (adrenal gland) in female embryo
female ovary, male differentiation of reproductive tract and genitalia
what happens at 6 weeks
sex specification starts
what is true of the early human embryo
not sex specified. internal and external reproductive system is identical till 6 weeks
both mullerian and wollfian tracts are present
what is SRY
a trascription factor- sex determining gene of the y chromosome for testes development
what is TDF
testis determining factor
what produces TDF
SRY
what develops first, the ecternal or internal reproductive organs
the external
what is gonadal sex determined by
presense of SRY gene
what are the two gonads
testis and ovaries
what leads to differentiation of internal reproductive tracts
AMH/ MIF and androgens
what does testosterone do in males for sex differentiation
promotes developemnt of external genitalia and internal tracts
what androgens are used for sex differentiation
testosterone and hihydrotestosterone (DHT)
what is AMH
antimullerian hormone
what secretes AMH
sertoli cells
when can you take an ultrasound for sex of baby
18-22 weeks
maturation of what continues until birth
sex specific reproductive tract and ecternal genitalia
what does the gential tubercle form in males
glans penis
what does the genital tubercle form in females
glans clitoris
what does the urethral folds form in females
labia minora, urethral opening, hymen , vagina, anus
what do the urethral forms form in males
anus and urethra
what do the genital swellings form in males
scrotum, penis shaft, prepuce,
what do the genital swellings form in females
labia majora
what does tstosterone do in males
form the internal reproductive tract
what does DHT do in males
form external reproductive organs
