Genital System Flashcards
what part of the mesoderm creates the genital system?
intermediate
T/F. The intermediate mesoderm becomes retroperitoneal.
True.
The intermediate mesoderm forms the bilateral _____ ______.
urogenital ridge
Each urogenital ridge is retroperitoneal and has what two portions?
nephrogenic cord and gonadal ridge
The ____ (medial/lateral) portion of the urogenital ridge contributes to the nephrogenic cord during the ___th week of development.
lateral; 4
The medial portion of the urogenital ridge contributes to the _____ ridge during the __th week of development.
gonadal; 5
weeks ___ - ___ are known as the indifferent stage of sexual development.
1 - 6
when is genetic sex determined?
at the time of conception
There is no visible differences between males and females until the ___th week.
7
What are the two genital ducts?
Mesonephric (Wolffian) and Paramesonephric (Mullerian) ducts
Primordial germ cells migrate to the gonadal ridge beginning at week ___ and arrive there by week ___.
4; 6
The _______ lining each gonadal ridge thickens and ______ cells become gonadal ____ cells.
mesothelium; mesothelia; cord cells
Cord cells form solid ____ ____ that sink into underlying ______ to “welcome” (envelop) primordial germ cells.
gonadal (cortical) cords; mesenchyme
What is the sex determining region of the Y chromosome?
SRY gene
What does the SRY gene code for?
TDF (testes-determining factor)
TDF induces the formation of what structures?
Leydig cells and Seminiferous tubules + Rete testes
where do Leydig cells develop?
from mesenchyme of gonadal ridge
At what week do cord cells form primitive gonadal (cortical ) cords?
6 week
Gonadal cords separate from the cortex and extend into the ____ of testicles to form _____ _____ and _____ ______.
medulla; seminiferous tubules; rete testes
what induces mesonephric ducts to form male genital ducts?
testosterone
what cells produce testosterone?
leydig cells
what does testosterone stimulate the formation of?
male genital ducts and external genitalia
what week does testosterone peek?
week 8
What are the three male genital ducts?
mesonephric duct, superior end of mesonephric duct, and mesonephric tubules
The mesonephric ducts becomes what structure?
ductus deferens
The superior end of the mesonephric duct develops into what structure?
epididymis
what does the mesonephric tubules create?
efferent ductules
The ____ ends of the mesonephric ducts develop into the seminal vesicles and ejaculatory ducts.
caudal
when does the descent of the testes begin and end?
begin at week 26
end at week 32 (testes in scrotum)
The ____ extends from the gonad to the labioscrotal swelling (future scrotal sac).
gubernaculum
As the gubernaculum ____, it pulls the testis, ductus deferens, and testicular vessels ____ through the abdominal wall (must traverse the inguinal canal) into the scrotal sac.
shortens; inferiorly
the pouch that forms around the 12th week that is carried into the scrotum by the descent of the testes is called the ____ _____.
processes vaginalis
the internal spermatic fascia is from the _____ fascia.
transversalis
the cremasteric fascia is from the _____ ____ muscle.
internal oblique
The external spermatic fascia is from the ____ ____ muscle.
external oblique
what is a congential inguinal hernia caused by?
a patent processus vaginalis
What develops in a hydroceoele of the testes / spermatic cord?
fluid-filled cysts
What condition is known as failure of the testes to descend?
cryptorchidism
what is formed if there is no SRy or TDF?
stromal cells and follicular cells
where do stromal cells develop from?
the mesenchyme of the gonadal ridge
Where do follicular cells develop from?
gonadal cord cells
follicular cells surround the primordial germ cells and form ____ _____.
ovarian follicles
when do oogonia become primary ooctes?
months 3 - 7
if there is low testosterone, what will regress?
mesonephric ducts
if there is no mullerin inhibiting hormone because there are no ____ ____, then what structure continues to grow and develop?
sertoli cells; mullerian (paramesonephric) ducts
what are the three remnants of the mesonephric duct?
epoophoron, parapphoron, gartner duct cysts
which remnant of the mesonephric duct is more superior? inferior?
superior - epoophoron
inferior - paraophoron
what structures are the gartner duct cysts located near?
cervix of the uterus
what structures will the Mullerian duct form?
uterine tubes, uterus, and superior vagina.
T/F. The mullerian duct forms the inferior vagina.
False, it forms the superior vagina
The ___ ends of the Mullerian ducts form the uterine tubes.
cranial
the caudal ends of the Mullerian ducts fuse to form the ____ ____, which will form the uterus and the superior portion of the vaginal canal.
uterovaginal primordium
the uterovaginal primordium contact the dorsal wall of the ____ ____ and induces the formation of a pair of endodermal outgrowths - the ____ ____.
urogenital sinus; sinovaginal bulbs
T/F. The sinovaginal bulbs separate from the urogenital sinus and fuse with the uterovaginal primordium.
true.
The ____ ____ plate becomes the inferior portion of the vagina.
vaginal plate
The urogenital sinus forms the ____ (superior/inferior) vagina.
inferior
The central ____ cells of the vaginal plate degenerate, forming the vaginal canal.
endodermal
what are the four endodermal outgrowths from the urogenital sinus?
- sinovaginal bulbs
- greater vestibular glands
- urethral glands
- paraurethral glands
T/F. The ovaries do not descend.
False. The ovaries descend, but not to the extent of the testes.
The ____ ____ is the superior part of the gubernaculum.
ovarian ligament
the ___ ____ of the uterus is the inferior part of the gubernaculum.
round ligament
Up to the ___th week, the external genitalia are similar in both sexes.
7th
when are the external genitalia fully differentiated?
week 12
Early in the ___th week, proliferating mesenchyme produces a ___ ___ (primordium of penis or clitoris) in both sexes at the ____ (crainal/caudal) end of the cloacal membrane.
4th; genital tubercle; cranial
Testosterone produced by ____ (Sertoli/Leydig) cells induces the differentiation of male external genitalia.
Leydig
what structures fold under ventrally and fuse to form the penile shaft?
urethral folds
The ____ ____ fuse at the midline to form the scrotum.
labioscrotal swellings
_____(endoderm/ectoderm)-lined distal spongy urethra meets _____(endoderm/ectoderm) lined proximal spongy urethra.
ectoderm; endoderm
The genital tubercle forms the ___ ___ in males and the ____ in females.
glans penis; clitoris
The urethra folds remain UNfused to form the ___ ___ in females.
labia minora
T/F. The labioscrotal swellings fuse posteriorly and anteriorly but remain unfused to form the labia majora.
True.
what cells produce Mullerian inhibiting hormone?
sertoli cells
What does mullerian inhibiting hormone do?
cause the mullerian (paramesonephric) ducts to regress
what is the mullerian duct remnant?
appendix testis