Development

Question 1

When is genetic/chromosomal sex determined?

Answer 1

At fertilization

Question 2

When is gonadal sex determined?

Answer 2

6 weeks

Question 3

When does the differentiation of the reproductive system begin?

Answer 3

6 weeks

Question 4

When can phenotypic sex be determined?

Answer 4

8 weeks

Question 5

What are the hormones involved in male reproductive system differentiation?

Answer 5

SRY, SOX9, testosterone

Question 6

What are the hormones involved in female reproductive system development?

Answer 6

RSPO1, WNT4, estrogen

Question 7

What does the undifferentiated gonad give rise to?

Answer 7

Both the testes and the ovaries

Question 8

What does the gonad originate from?

Answer 8

The genital ridge

Question 9

What is the genital ridge?

Answer 9

It is a thickening of intermediate mesoderm covered by coelomic epithelium

Question 10

What is the role of the primordial germ cells in the reproductive system?

Answer 10

They emigrate to the gonads and primitive sex chords

Question 11

What happens if the primordial germ cells fail to reach the genital ridge?

Answer 11

The gonads do not development

Question 12

What is responsible for ovarian development?

Answer 12

The DAX-1 gene on the short arm of the X chromosome

Question 13

Which cell in the biopotential gonad is responsible for producing testosterone?

Answer 13

Leydig cells

Question 14

What cell in the biopotential gonad is responsible for producing oestrogen?

Answer 14

Granulosa/follicular cells

Question 15

What is essential for male development?

Answer 15

The Y chromosome and the presence of SRY

Question 16

Describe the relationship between the mesonephric and paramesonephric ducts

Answer 16

They are a competing system where one must be eliminated for the other to differentiate

Question 17

How does testosterone act on the reproductive system?

Answer 17

It acts directly on the mesonephric duct to drive differentiation into male genital ducts

Question 18

What are the effects of fetal testosterone?

Answer 18

1. Retention of a subset of mesonephric tubules as efferent ductules of the rete testis
2. Persistence of the mesonephric duct and differentiation into epididymis, vas deferens, seminal vesicle and ejaculatory duct

Question 19

What causes degeneration of the paramesonephric ducts?

Answer 19

Antimüllerian hormone (AMH)

Question 20

What is the remnant of the uterus in males?

Answer 20

The Utriculus prostaticus

Question 21

What are the remnants of the degenerated paramesonephric ducts in males?

Answer 21

The appendix epididymis and the appendix testis

Question 22

What does the craneal portion of the paramesonephric duct differentiate into?

Answer 22

The uterine tubes

Question 23

What does the caudal portion of the paramesonephric duct differentiate into?

Answer 23

They fuse to from the uterus

Question 24

What must be removed during the forming of the uterus?

Answer 24

The uterine septum

Question 25

What is responsible for the development of the external male genitalia?

Answer 25

Dihydrotestosterone (DHT)

Question 26

What is the function of dihydrotestosterone?

Answer 26

It stimulates development of the external male genitalia

Question 27

What cause the differentiation of the external female genitalia?

Answer 27

The absence of DHT

Question 28

What are the phases of testicular descent?

Answer 28

1. Transabdominal phase

2. Transinguinal phase

Question 29

Describe Cryptorchidism

Answer 29

Undescended testes

Question 30

Describe ectopic testes

Answer 30

Testes that are in an abnormal location

Question 31

What is Swyer Syndrome?

Answer 31

The presence of XY chromosomes in females

Question 32

What is Turner syndrome?

Answer 32

The absence of one X chromosome (X,0) in females

Question 33

What is a possible cause of Swyer syndrome?

Answer 33

Mutation on SRY gene