Embryology of repro system Flashcards
The gonads begin as indifferent strctures. Male/female differentiation is then triggered by germ cells - T or F?
True
What are the reproductive organs developed from ?
From the intermediate mesoderm
What does development of the male reproductive system require the expression of ?
Requires expression of SRY- the sex determining region of the Y chromosome
What does the male repro system specifically originate from ?
Mesophrenic ducts - also called wolffian duct
What does the female repro system originate from ?
Paramesophrenic ducts also known as mullerian duct
Describe the hormonal control of the development of the male repro system
Developing male gonads have sertoli cells which produce Mullerian inhibiting substance which suppresses development of the mullerian duct.
They also have leydig cells whcih produce testosterone which stimulates development of the wolffian duct into internal genitalia
Testosterone produced is also converted into dihydrotestosterone which stimulates the development of external genitalia
What controls the descent of the testis from abdomen to scrotum ?
Gubernaculum
Describe the hormonal development of the female repro system
Developing ovary/gonad produces estrogen (so does the mother and placenta)
- This stimulates paramesophrenic (mullerian) ducts to develop into the internal genitalia
- This also stimulates the external genitalia to develop
How are the ovaries moved in female repro development ?
Moved by the gubernaculum (remember ovaries and testis develop from same thing just depends on sex of fetus)
it pulls them down into the peritoneal fold
What do the paramesophrenic ducts along with developing into the internal genitalia do ?
Fuse to form the broad ligament of the uterus
After moving the position of the ovaries what goes the gubernaculum in females form ?
Forms into the proper ovarian ligament and the round ligament of the uterus
What are some of the abnormalities that can arise from uterine development from the paramesophrenic ducts ?
- Uterus didelphys
- Uterus arcuatus
- Uterus bicornis
- Uterus bicornis unicollis
- Atresia of the cervix
- Atresia of the vagina
The external genitalia are the same as the internal and have an ‘indifferent’ stage before male/female differentation - T or F?
True
Describe how the cloaca contributes to the urinary, repro and GI systems
In 3rd week cloaca folds form, fusing cranially to form genital tubercle
In 6th week cloacal membrane divides into urogenital and anal membranes and the cloaca folds divide into urethral and anal folds
What do the genital swellings form ?
The scrotum in males
The labia major in females
Appreicate the further development of the male external genitalia
Appreicate the further development of the female external genitalia
What in terms of development can led to developmental anomalies between the urinary, repro and GI systems ?
The common origin in the external parts of these systems
What are some of the developmental abnormalities of the urogenital and hindgut systems ?
- urorectal fistula
- rectovaginal fistula
- rectoperineal fistula
