Repro Embryology Flashcards
The cloaca divides to form what?
Rectum and Urogenital sinus
The mesonephric duct drains into what?
Urogenital sinus
The urogenital sinus formw what?
Urinary bladder
Caudal end - urethra
What are the types of early kidney at 5 weeks?
Pronephros Mesonephros Metanephros - Ureteric bud - Metanephric mesoderm
The medial part of the mesonephric ridge becomes thickened to form what?
Genital/gonadal ridge
Germ cell migration into genital ridge forms what?
Indifferent gonad
no migration means no gonads
Epithelium of the mesonephros invaginates to form what?
The para-mesonephric duct
What happens at the paramesonephric duct?
Develops lateral to the developing gonads and mesonephric duct
Projects into dorsal wall of urogenital sinus
What are the 3 major embryologial structures of the reproductive tract?
Indifferent gonad
Mesonephric duct
Paramesonephric duct
Urogenital sinus
What does the indifferent gonad form in males?
Testis
What does the indifferent gonad form in females?
Ovary
What does the mesonephric duct form in males?
Epididymis
Vas deferens
Seminal vesicle
What does the paramesonephric duct form in males?
It degenerates
What does the urogenital sinus form in males?
Bladder
Urethra
Prostate
What does the mesonephric duct form in females?
It degenerates
What does the paramesonephric duct form in females?
Uterus
Fallopian tubes
Uterus
Cervix
What does the urogenital sinus form in females?
Bladder
Lower part of vagina
How is testes formation determined genetically?
Sex determining region Y on Y chromosome leads to development of Sertoli cells
Sertoli secrete Mullerian-inhibiting-substance
Paramesonephric duct degenerates
MIS causes Leydig cell formation
Testosterone –> MAN
Where do the Seminal Vesicles originate?
Outgrowth from the end of the mesonephric duct
Where does the prostate originate?
Outgrowth from urethra (urogenital sinus)
The indifferent gonad develops into what by default?
Ovary
What protein causes testis formation?
TDF - Testis determining factor (encoded in SRY on Y chromosome)
How many primordial follicles do females have at birth?
2 Million
How many follicles are developed per menstrual cycle?
12-15 days
Absence of testosterone causes what in the tubular components?
Degeneration of mesonephros + mesonephric duct
Paramesonephric duct develops
The cranial end of the paramesonephric duct forms what?
Ovary
The caudal end of the paramesonephric duct forms what?
Uterus
Superior part of vagina
What forms the inferior part of the vagina?
Urogenital sinus
At what vertebral level do the gonads form?
T10
Outline the descent of the testis?
Wk 7 - T10
Wk 12 - Deep inguinal ring
Wk 39 - Enters scrotum
Outline the descent of the Ovary?
Wk 7 - T10
Wk 12 - Broad ligament
Round ligament drawn through inguinal canal
What do parents notice in Cryptorchidism?
Testes that are: Undecended Ectopic Retractile Absent
What complications are associated with Cryptorchidism?
Infertility
Germ cell tumours
Testicular torsion
