Embryology

Question 1

Which layer of the 3 layer embryo does the reproductive system originate?

Answer 1

• intermediate mesoderm

Question 2

The urogenital ridge forms what?

Answer 2

• gonads

- ductal system

Question 3

What is the common embryological cavity in the urogenital system

Answer 3

• cloaca

Question 4

The urinary system is more __medial/lateral__ than the genital

Answer 4

• lateral

Question 5

When does sex differentiation appear?

Answer 5

• after week 7

Question 6

Ductal system in males?

Answer 6

• mesonephric

- aka. wollifian

Question 7

Ductal system in females?

Answer 7

• paramesonephric

Question 8

In terms of sex differentiation in the gonadal system, female changes occur where compared to males?

Answer 8

• female - cortex

- male - medulla

Question 9

What gene leads to sex differentiation?

Answer 9

• SRY gene

(sex, region, y) transcription factor, presence leads to testes determining factor

Question 10

Male development is triggered by what?

Answer 10

• SRY gene

Question 11

Sertoli cells release?

Answer 11

• AMH hormone

- segregates the paramesonephric ducts

Question 12

Leydig cells secrete what?

Answer 12

• testosterone

- maintenance and growth of the mesonephric ducts (epididymis, vas deferents etc)

Question 13

What hormone is responsible for the development of the external male genitialial?

Answer 13

-testostorone - dihydrotestosterone

Question 14

Describe the formation of the external male genitalia?

Answer 14

• proximal to distal zipping of the urethral groove

- forms the stony urethra

Question 15

Define hydrospadius?

Answer 15

• abnormal external urethral opening on ventral aspect of penis

Question 16

Follicular cell development in females in caused by what?

Answer 16

• absence of SRY gene
• follicular development
• leads to oestrogen secretion

Question 17

Oestrogen is responsible for what in female development?

Answer 17

• external genital

- maintenance of paramesonephric ducts

Question 18

Which stage is the primordial follicles halted in?

Answer 18

• prophase 1

Question 19

3 regions of the paramesonephric ducts?

Answer 19

• cranial (opening into the peritoneal cavity)
• horizontal (crosses mesonephric duct)
• caudal (fuses with duct on opposite site, forming uterovaginal canal)

Question 20

What guides descent of the gonads in males and females?

Answer 20

• gubernaculum

Question 21

Cryptorchidism?

Answer 21

• failure in descent of the testes

- gubernaculum normally aids descent