repro embryology Flashcards
where do primordial germ cells migrate to
gonadal ridge
what 3 types of cells are found in gonadal ridge
primordial germ cells
mesothelial cells
mesenchymal cells
what do primordial cells give
future gametes
male = spermatogonia
female = oogonia
what do mesothelial cells do
structures which will harbour and help in development of primordial germ cells
what structures are mesothelial cells in M&F
male = seminiferous tubules
female = follicles
what are mesenchymal cells
supporting cells
male = Leydig cells
female = stroma
which layer is genital tract developed from
intermediate mesoderm
what are the 2 genital ducts
mesonephric - Wolffian (male)
paramesonephric - Mullerian (female)
give internal reproductive structures
what structures does mesonephric (wolffian) duct give
epididymis
vas deferens
seminal vesicle
what structures does paramesonephric (Mullerian) duct give
uterus
fallopian tube
cervix
upper 1/3 vagina
dihydrotestosterone function
provides prostate, penis and scrotum
external genitalia
what does sertoli cells produce
MIF
gubernaculum becomes what?
ovarian ligament and round ligament of ovary
what week do germ cells begin to migrate from endoderm lining of yolk sac to genital ridges
4th week
what week do the germ cells reach the genital ridges
6th week
what forms indifferent gonad
germ cells and primitive sex cords
how do primitive sex cords form
epithelium of genital ridges proliferates and penetrates the intermediate mesoderm
what gene does Y chromosome contain
SRY
what does SRY gene do
stimulate development of primitive sex cords to form testis (medullary) cords
a portion of testis cords breaks off to form what
future rete testis
remaining testis cords contain 2 types of cells
sertoli
germ
Leydig cells are derived from?
intermediate mesoderm
what do Leydig begin in week 8
production of testosterone - which drives differentiation of internal and external genitalia
role of appendix testis and location
no physiological function
small portion of tissue located on upper pole of each testicle
how does appendix testis form
paramesonephric duct
in the presence of which hormone does paramesonephric duct degenerate
anti-Mullerian
where is anti-Mullerian hormone produced
sertoli cells in the testes
in females, what does the degeneration of mesonephric duct leave behind
vestigial remnant: Gartner’s duct
absence of anti-Mullerian hormone allows for development of what duct
paramesonephric duct
3 parts of paramesonephric duct
cranial
horizontal
caudal
cranial paramesonephric duct becomes?
fallopian tubes
horizontal paramesonephric duct becomes?
fallopian tubes
caudal paramesonephric duct becomes?
fuses to form the uterus, cervix, and upper 1/3 vagina
how does lower 2/3 vagina form
sinovaginal bulbs
where are sinovaginal bulbs derived from
from pelvic part of urogenital sinus
which week does external genitalia development begin
3rd week
how are cloacal folds formed
mesenchymal cells from primitive streak migrate to cloacal membrane to form pair of cloacal folds
cranially, what do folds do?
fuse to form genital tubercle
caudally, what do folds do?
divide into urethral folds (anterior)
anal folds (posterior)
what develops either side of urethral folds
genital swellings
rapid elongation of genital tubercle causes what to form
becomes the phallus
urethral folds are pulled to form what
urethral groove
folds close over by when and form what
by 4th month and form the penile urethra
genital swellings become what
scrotal swellings
scrotal swellings move where to form what
move caudally to form scrotum
oestrogens are responsible for ?
external genitalia development
genital tubercle elongates to form what
clitoris
urethral folds and genital swellings do not fuse, but instead form what
labia minora and labia majora respectively
urogenital groove remains open, forming what?
vestibule into which urethra and vagina open
gubernaculum
ligamentous structure formed from mesenchyme
around week 28 what happens with testes
pass through inguinal canal
testes reach scrotum at what week
week 33
testes blood supply
testicular arteries
where do testicular arteries branch from
lumbar aorta
adult remnant of gubernaculum in males
scrotal ligament
