Genital System Flashcards
from what three sources are the gonads derived
mesothelium on posterior abdominal wall
mesenchyme underlying the mesothelium
primordial germ cells
What makes up the gonadal (urogenital) ridge
proliferation of mesothelium and underlying mesenchym medial to mesonephros
form longitudinal bulge
From where do the primordial germ cells come
from ubilical visicle through the dorsal mesentery
to invade gonadal ridge
What does the mesothelium proliferate into and when
epithelial cords (gonadal cords) which grow into mesenchyme
6th week
What do the gonadal cords invest
germ cells
at the 6th week what makes up theindifferent gonad
outer cortex with gonadal cords and
inner medulla primarily of mesenchyme
before what week are the gonads still indistinguishable
week 7
What hppens in week 7 to start gonadal differntiation
protein encoded by sry gene on y chromosome is produced
What is the the protein encoded by SRY
testis determining factor
What synthesizes the sry/tdf
presertoli cells of gonadal cords
If sry is absent or defective what occurs
female development
What are the 3 events that occur as a result of sry influence
gonadal cords condense and extend into medulla
Thick fibrous capsule interrupts the connection of gonadal cords with surface epithelium
Leydig cells develop from mesenchymal cells within genital ridges
What forms as a result of gonadal cords being affected by sry
Rete testis
from the extension branching and anastomoses of condesnesed cords in medulla
What do the gonadal cords differentiate into
Sertoli cells
What do the seroli cells organize and align with and what do they derive from
Spermatagonia
from primordial germ cells
What is created from the organization of sertoli cells and speramtagonia
seminiferous cords
What triggers the transition from seminiferous cords to tubles
puberty
lumina forms in cords
What interrupts the connection of the gonadal cords with the surface epithelium
tunica abuginea
What do leydig cells develop from
mesenchymal cells in genital ridges
What do leydig cells secrete and why is it important
testosterone
impotant for differentiation of male genital duct system from mesonephric duct system
What do sertoli cells secrete and what does it do
Antimullerian homrmone or Mullerian inhibiting substance
supresses development of paramesonephric (mullerian) ducts
When does the indiffernt gonad become an ovary
in the 10th week without testis diff signals
Which gonadal development lags behind the other
ovary lags behind testies
When does ovarian differentiation begin (cords)
when gonadal cords degenerate and cortical cords develop
where do cortical cords extend
from surface epithelium to underlying mesenchyme
What happens as the cortical cords increase in size
oogonia undergo mitosis and are incoporated into the cortical cords
what doe oogonia derive from
primordial germ cells
What do the the cortical cords break up into
isolated clusters each containing oogonium
What happens once the cords break up
oogonia enter meiosis and are called primary oocytes
Once the oogonia become primary oocytes what surrounds them and what is it derived from
singly layer of flattened epithelial cells
from cortical cords
What is the name for the association of oocytes and epithelial cells
Primordial follicles
In what phase are oocytes pausesd
first meiotic division
when does th oocyte resume meiosis
once it is stimulated to develop during the reproductive lifespan of a woman
When do oogonia form postnatally
they dont
What are the two ducts that are initally present as presumptive geital ducts
mesonephric (wolffian)
Paramesonephric (mullerian)
If nothing is secreted what presumptive geneital duct progresses
paramesonephric duct and mesonephric regress
What causes the paramesonephric duct to regress and mesonephric to sustain
testosterone stimulates meso
MIS causes Para to degen
What forms into efferent ductules
some mesonephric tubules of the degenerating mesonephric kidney
What is formed from the cranial part of the mesonephric duct and what does it connect with
epididymis
efferent ductules
What forms from the non cranial portion of the mesonephric duct
vas deferens
what gives rise to the seminal vesicle
outgrowth from the caudal end of the mesonephric duct
What is the part of the mesonephric duct distal to each seminal gland
ejaculatory duct
What does the glandular portion oof the prostate develop from
endodermal outgrwoths of the prostatic urethra
What is the stroma and smooth muscle of the prostate derived from
mesoderm
What do the bulbourethral glands arise from
endodermal outgrowths from the urethra
distal to prostate
When do th paramesonephric ducts from wand where
6th week
lateral to the mesonephric ducts
how are the paramesonephric ducts formed
invagination of colemic epithelium in craniocaudal sequence
what gives rise to most of the female genital tract
paramesonephric ducts
What arises from the paramesonephric ducts cranially
open into the coelom and form uterine tubes
What arises from the fusion of the paramesonephric ducts caudaly
uterus and upper part of vagina
What also arises from the fusion of the paramesonephric ducts
broad ligament of uterus
what does the broad ligament of the uterus partition
lower peritoneal cavity into vesicouterine and rectouterine puches
fused ends of the uterovaginal primordia contacting postieror inferior wall of urogenital sinus causes what
induced formation of a thickining called the sinus tubercle
What does the sinus tubercle form
proliferates and forms swellings called sinovaginal bulbs
What do the sinovaginal bulbs form and how
extend caudally and fuse to form solid vaginal plate
What does the vaginal plate form
canalizes to form lower part of vagina
what forms in the female as a result of endodermal outgrowth from the pelvic portion of the urogenital sinus (3)
urethral
paraurethral
greater vestibular glands
