Development of the Genital System Flashcards
what embryonic origin is the genital system, as well as most of the urinary system
intermediate mesoderm
during what week does the lateral body folding of the embryo cause the intermediate mesoderm to go retroperitoneal
week 4
the intermediate mesoderm develops a bilateral urogenital ridge (urinary slightly before genital), what are the 2 portions of this ?
- nephrogenic cord
- gonadal ridge
which is located more lateral to the midline, the nephrogenic cord or the gonadal ridge
nephrogenic cord
what weeks are considered the indifferent stage of sexual development
1-6
Which set of ducts are present during the indifferent stage of sexual development
- Mesonephric duct (Wolffian)
- paramesonephrict duct (Mullerian)
- both
Both are present at this time
which genital duct gives rise to male structures and which to women ? what are the specific features ?
mesonephric duct ——> vas deferens
paramesonephric duct ——–> fallopian tubes
what is another name for the mesonephric duct, how about paramesonephric duct
mesonephric duct = Wolffian duct
paramesonephric duct = Mullerian duct
at what week can you notice a visible difference b/w male and female sexual development
week 7
Primordial germ cells (PGC) begin migrating at week ____ and reach the gonadal ridges at week _____
4, 6
what are known as the “welcoming wagons” for the primordial germ cells once they reach the gonadal ridges
Gonadal cord cells
what is the embryonic origin of gonadal cord cells
thickened mesothelial lining cells from the gonadal ridge
what is the SRY gene and who has it
sex determining region of the Y chromosome
-males
what does the SRY gene code for
TDF protein
-testis-determining factor
Testes determining factor TDF, stimulates the development of what cells from the mesenchyme of the gonadal ridge
Leydig cells
what is the function of Leydig cells and who has them
produce testosterone, men
what is the function of Sertoli cells, and who has them
caretakers of the primordial germ cells, men
Sertoli cells develop from where
gonadal cord cells after they have enveloped the PGC
when the gonadal cord cells envelope the primordial germ cells what two things form ?
seminiferous tubules + Rete testes
the superior end of the mesonephric duct eventually develops into what ?
epidiymis
the mesonephric tubules eventually develop into what ?
efferent ductules
the production of testerone via the Leydig cells stimulates the formation of what
male genial ducts and external genitalia
the caudal ends of the mesonephric duct develop into what 2 things
- seminal vesicles
- ejaculatory ducts
the very caudal ends of the mesonephric duct continue to develop into the posterior wall of the urinary bladder, this are is called
trigone
how do the male accessory organs, the prostate and bulbourethral gland, develop
endodermal outgrowths from the urogenital sinus
what hormone do Sertoli cells produce, and what does this hormone do ?
Secretes Mullerian-inhibiting hormone (MIH)
-causes the paramesonephric duct (Mullerian duct) to degernerate in males
if there is a little remnant of the Mullerian duct in males from not fully degenerating this is referred to as ?
appendix testis
what week does the descent of testis start
week 26
how do the testes decend
the gubernaculum ligament shortens which pulls down with it the testis, vas deferens, and testicular vessels
where does the gubernaculum ligament extend to
from the gonad to the labioscrotal swelling
what does the labioscrotal swelling develop into in males, females ?
males - scrotum
females the labia majora
the inferior path of the testis due to the shortening of the gubernaculum ligament is eventually referred to as the
inguinal canal
what are the 3 layers of the spermatic cord, and what are they derived from
- internal spermatic fascia (transversalis fascia)
- cremaster fascia (internal oblique m.)
- external spermatic fascia (external oblique m.)
what is a hydrocoele of the testis or spermatic cord
fluid filled cyst w/in testis or cord
what is a congenital inguinal hernia
outpouching of abdominal viscera which could lead to scrotum
what is cryptochidism, and what causes this
failure of testis to descend
-lack of testosterone via Leydig cells
what cells of the ovary develop from the mesynchyme of the gonadal cells
Stromal cells
what are the equivalent caretakers of the primordial germ cells for females just like sertoli cells in males
follicular cells
what causes the mesonephric duct to regress in the development of the female genital systems
Lack of testosterone hormones
what causes the continued growth and development of the Mullerian duct in female genital dev.
lack of MIH secreted by sertoli cells
what makes up the primordial follice in females
primary oocyte + follicle cell capsule
if there are mesonephric duct remnants in the development of female genital systems, this can lead to what 3 things ?
- epoophoron
- paraophoron
- gartner duct cyst
the cranial ends of the mullerian ducts form what
uterine tubes/fallopian tubes
the caudal ends of the mullerian duct fuse together to form what ?
uterovaginal primordium
what does the uterovaginal primordium develop into
the uterus and superior vagina
what does the inferior vagina develop from
urogenital sinus
what are sinovaginal bulbs
endodermal outgrowths from the urogenital sinus in females which develops into the vaginal plate which leads to the development of inferior vagina
the accesory organs of the female genital system consist of the greater vestibular glands, urethral glands, and the paraurethral glands. These all form how
endodermal outgrowths from the urogenital sinus
the descent of the ovaries uses the gubernaculum ligament just like males, how is the process different
when is shortens it splits in two because of the development of the uterus
what are the derivatives of the gubernaculum ligament in females after it divides via uterus development
superior gubernaculum = ovarian ligament
inferior gubernaculum = round ligament of the uterus
what does the genital tubericle develop into in males and females
males - glans penis
female - clit
during development the cloacal membrane divides into what 2 folds
urethral fold and anal fold
what do the urethral folds develop into in males and females
males - fuse to form shaft of cock
females -remain unfused as labia minor
