1.1 Development of the reproductive tract Flashcards
Describe the components of the male internal genitalia
Testis Duct system (epididymis, ductus deferens, urethra)
Seminal vesicles
Prostate
Bulbourethral glands

What is the purpose of the male internal and external genitalia
Internal: collect and mature sperm
External: deliver ejaculate semen into the vagina during coitus
Describe the components of the female internal genitalia
Ovaries
Duct system (Fallopian tube, uterus, cervix, vagina)

What is the purpose of the female internal and external genitalia
Internal: produce ovum and provide optimal environment for sperm
External: allow the introduction of sperm into the female reproductive tract and allow formation of a birth canal
Compare the male vs female EXTERNAL genitalia
Male:
- Penis
- Scrotum
Female:
- Vagina
- Vestibule
- Labia minora
- Labia majora
- Clitoris

What is meant by the indifferent stage of of reproductive development?
Initial stage in both male and female begins the same
Depending on the expression of genes has the potential to become either male or female
What is the difference between structural and functional development?
Structural: occurs in utero
Functional: continues after birth
List 3 things that will develop/not develop if the primordial germ cells express XY on an indifferent gonad
Develpment into testis (male)
- Medullary cords develop
- No cortical cords
- Thick tunica albuginia
List 3 things that will develop/not develop if the primordial germ cells express XX on an indifferent gonad
Development into ovaries (female)
- Medullary cords degenerate
- Cortical cords develop
- No tunica albuginea
The primordial germ cells are formed in which layer of the trilaminar disc and during which week?
epiblast, 2nd week
What region/gene is specific to only the Y chromosome?
What does expression of this do?
SRY region (Sex determining region) / TDF (Testis determining factor)
Directs testicular formation
Absence of a Y chromosome (ie. XX) means what gene will be absent and what will occur as a result?
Absence of the SRY region
Directs development of a female (ovaries, tubes, uterus + external female genitalia)
At what week do we get migration of the PGC’s (primary germ cells)
week 3
Where do the PGC’s originate and how do they migrate?
Originate in the wall of the yolk sac
Migrate along the wall of the hindgut and dorsal mesentery into the genital ridge

Where is the urogenital ridge found?
What is found either side of this ridge and what is the fate of these?
Found on the dorsal body wall
Laterally: mesonephric ridge ➞ kidneys
Medially: genital ridge ➞ ovaries/testis

The genital ridge consists of two components, what are these?
Mesenchyme
Coelomic epithelium
What are the 3 sources of gonadal development?
1) condensed mesenchyme of gonadal ridges (plica genitalis)
2) coelomic epithelium (mesodermal origin)
3) gonocytes (primordial cells)
Male internal genitalia develop from what duct?
Wolfian/ Mesonephric duct
Female internal genitalia develop from what duct?
Mullarian/ Paramesonephric duct
Explain gonadal development in the presence of SRY (TDF)
1) Gonadal cords develop ➞ expression of TDF leads to the growth of sex chords into the medullary region of the gonad
* primordial germ cells enter these cords and give rise to seminiferous tubules in an adult
2) No cortical cords develop
3) A Thick Tunica Albuginea forms
Explain gonadal development in the absence of SRY (TDF)
1) Gonadal cords degenerate (leaves space for oogonia to develop)
2) Cortical cords develop
3) The germ cells become surrounded by mesenchymal cells to form primordial follicles
*** No Tunica Albugina
What is the gubernaculum and what is its purpose?
Undifferentiated band of mesenchyme that guides the decent of the gonads
After atrophy of the mesonephros, what happens to the proximal (upper) portion of the gubernaculum in males vs females?
Males: disappears
Females: forms the ovarian ligament (connecting ovary to uterus)
After atrophy of the mesonephros what happens to the distil (lower) portion of the gubernaculum in males vs females?
In both, it inserts at a lower pole of gonad and extends to the inguinal region
Males: becomes the scrotal ligament
Females: becomes the round ligament of the uterus (connecting the uterus to the labia)



