[Music]
hi today we're going to talk about
female puberty milestones first let's
talk about the different types of sex
there are three types of six genetic sex
gonadal sex and phenotypic sex first
let's talk about genetic sex genetic sex
is your X X or X Y X 46 X X being female
46 XY being male that sex usually and
typically determines your gonadal sex
gonads can be either ovaries or testes
those ovaries or testes make hormones
the hormone production during fetal
development or the hormone production
during puberty will determine external
phenotype those differences will also be
seen in the brain and during fetal
production of hormones you get sexual
differentiation of the external
genitalia that leads to sex assignment
at birth and gender rearing while at
puberty sexual secondary sexual
development is due to the production of
hormone either from the testes or
ovaries which leads to gender identity
the genetic sex determination is made by
again XY in the mail or X X and the
female there are certain genes that are
upregulated or downregulated depending
on whether there is the presence of a Y
the Y chromosome encodes sry sry we'll
down regulate the genes that are
important for female development went
for and RSPO one and will up regulate
sox9 and fgf 9 and the sertoli cells
while in the female socks 9 and fgf 9
are not present therefore went for and
RSPO one will be upregulated this will
lead to a female phenotype in the gonad
or in the ovaries of the female who
agenesis occurs the genesis begins
around the fourth week of gestational
age around the mid gestation around 20
weeks you will see that allah Gonia the
cells that produce
we'll begin to make follicles those
follicles will undergo a process called
atresia or apoptosis or programmed cell
death which will decrease the number of
follicles that are present which will
continue to decrease throughout the life
of the female fetus now depending on
whether or not you have sertoli cells
that make a MH or anti-mullerian hormone
you will develop either pair of mutant F
rows in the female or means an F rows in
the mail
we both though start out with an in
differentiated stage and in the female
pair mutant f rows equals the malaria
duct and the male
the reason F rows equals the wolffian
ducts so normally in the female you
don't have a MH produced by the sertoli
cells and therefore you make fallopian
tubes a uterus and an upper third of the
vagina however if you are male you do
produce a MH from the sertoli cells and
those to troll yourself inhibit malaria
development or para means and afros in
the mail you will see me the network
ducts which lead to the epididymis the
vas deferens and the urethra now if your
gonads produce testosterone or estrogen
that will make your phenotypic sex or
the sex that you show with your external
differentiated genitalia in the female
the glans penis will become the clitoris
the labia scrotal Ridge will actually
not use and there will be an enjoyed us
for the vagina you will have a labia
minora and a labia majora however in the
male testosterone DHT to be specific
causes the glans to become the penis you
will see that the laborer scrotal
swelling will become the scrotum and
that there will be a fusion of the labor
scrotal foals so that you have a penile
Rafi in the female fetus in the first
trimester germ cell migration occurs you
can also see that there's development of
the external genitalia the wolffian
ducts should be
generate leading into the second
trimester there's development of a
uterus and onto the vagina now let's
look at male development in the first
trimester you see that there's germ cell
migration spermatogenic cords this is
also late Excel development which will
make testosterone this differentiation
of the external genitalia
this also wolfing duct differentiation
and remember that the pair means an
ethros or the malaria ducts will regress
you see here in the second trimester
that we have testosterone synthesis and
that will cause the growth of the
external genitalia and the descent of
the testes from the abdomen into the
scrotum normally you'll see
pediatricians will check for the descent
of testes at the time of birth
[Music]