Development of Reproductive Tract

Question 1

what determines gonadal development

Answer 1

presence of Y chromosome (SRY region and Sox9 gene)

by default would be female

Question 2

XXY example
XO example

Answer 2

XXY - male calicos, testes
XO - turner’s syndrome, ovaries

Question 3

sertoli and granulosa cells originate from…

Answer 3

sex cords

Question 4

leydog and theca cells originate from…

Answer 4

mesenchyme

Question 5

Wolffian (mesonephric) duct precursor to what?

Answer 5

male internal genitalia
- epididymis
- vas deferens
- urethra

Question 6

Mullerian (paramesonephric) duct precursor to what?

Answer 6

female internal genitalia
- oviduct
- uterus
-cervix

Question 7

development of male internal genitalia depends on the presence of what hormones

Answer 7

presence of testosterone
presence of anti-mullerian hormone

Question 8

development of female internal genitalia depends on the absence of what hormones

Answer 8

absence of high testosterone
absence of anti-mullerian hormone

Question 9

what cells secrete testosterone that allows development of Wolffian ducts

Answer 9

Leydig cells

Question 10

what cells produce AMH resulting in regression of Mullerian ducts

Answer 10

Sertoli cells

Question 11

external genitalia - precursor tissues are _____

Answer 11

bipotential - can develop into either male or female

Question 12

what determines the masculinization of external genitalia

Answer 12

androgen dihydrotestosterone (DHT)
T converted to DHT via 5alpha-reductase

Question 13

what does DHT direct the formation of

Answer 13

penis
scrotum

Question 14

what determines the feminization of the external genitalia

Answer 14

absence of DHT = clitoris and labia

Question 15

male genitalia (both internal and external) is dependent on what 3 hormones

Answer 15

testosterone
AMH
DHT

Question 16

what has both ovarian and testicular tissue present?

what species is this most common in?

Answer 16

hermaphrodite

swine

Question 17

what has testes + female external genitalia

Answer 17

male pseudohermaphrodite

Question 18

what has ovaries + male external genitalia

Answer 18

female pseudohermaphrodite

Question 19

what are characteristics of androgen resistance syndromes?

Answer 19

XY, bilateral testes, normal regression of mullerian ducts and normal secretion of T BUT have female external genitalia

Question 20

2 forms of androgen resistance syndromes

Answer 20

1. 5alpha-reductase deficiency
2. androgen receptor dysfunction (underdeveloped Wolffian ducts)

Question 21

what is freemartinism

Answer 21

• intersex female calf born co-twin to male
• requires anastomoses (so T and AMH go to female)

Question 22

female fetus of freemartinism vs male fetus

Answer 22

hypoplastic ovaries
may contain seminiferous tubules
hypoplastic female external genitalia
wolffian duct derivatives present
infertile

male - minimally affected

Question 23

what causes testicular descent into the scrotum

Answer 23

regression of gubernaculum (androgen dependent)

Question 24

why are bilateral cryptorchids azoospermia (sterile)

Answer 24

elevated testicular temp