Reproductive Development- Severson

Question 1

What gene is responsible for the production of testis-determining factor?

Answer 1

SRY gene located on Y chromosome

Question 2

What causes Kinefelter Syndrome?

Answer 2

47, XXY

Due to nondisjunction of the XX homologues

Characterized by infertility, gynecomastia, and impaired sexual maturation

Question 3

Describe Turner’s Syndrome

Answer 3

45, XO

Gonadal dysgenesis

Short stature, webbed neck, broad and shield-like chest, absence of sexual maturation, cardiac and renal anomalies

Question 4

What does the urogenital ridge arise from?

Answer 4

Intermediate mesoderm

Question 5

At what point in development do the gametes migrate from the umbilical vesicle to the genital ridge to give rise to the gonads?

Answer 5

5th week

Question 6

What portion of the developing embryonic mesoderm gives rise to the gonadal or genital ridge?

Answer 6

Intermediate mesoderm

Question 7

What transcription factor is responsible for the cortical cords differentiating into seminiferous tubules?

Answer 7

Testis-determining factor

Question 8

What is the most common abnormality of sexual differentiation?

Answer 8

Klinefelter Syndrome

Usually due to non-dysjunction of the XX homologues

Question 9

Which of the following is NOT involved in the development of the testes?

A. Genital ridge
B. SRY gene
C. Testis-determining factor 
D. X-chromosome
E. Y-chromosome

Answer 9

D. X Chromosome

Question 10

Which of the following genotypes is characteristic of individuals with Klinefelter syndrome?

A. 46 XY
B. 47 XXY
C. 45 YO 
D. 46 YY
E. 45 XO

Answer 10

B. 47 XXY

Question 11

Which of the following phenotypes is NOT characteristic of individuals with Turner syndrome?

A. Inverted nipples
B. High-arched palate
C. Shield-like chest
D. Short statue
E. Small penis
F. Web neck

Answer 11

E. Small Penis

Question 12

What 3 things make up the developing gonads?

Answer 12

1. Mesothelium (coelomic epitheium)
2. Mesenchyme (under lying the mesothelium)
3. Primordial Germ Cells

Question 13

Describe the path of the primordial germ cells in the developing fetus

Answer 13

Primordial germ cells originate in the umbilical vesicle (yolk sac)

Migrate along dorsal mesentery to the genital ridge/ cortical cords

Undergo mitoses during migration

Question 14

What forms the follicular cells in the female?

Answer 14

Primordial cortical cords break apart to form the follicular cells that surround the oogonia

Question 15

Which of the following serve as the developmental site of the primordial or primitive germ cells?

A. Dorsal mesentery
B. Gonadal ridge
C. Intermediate mesoderm (mesenchyme)
D. Mesothelium
E. Urogenital ridge
F. Umbilical vesicle (Yolk sac)

Answer 15

F. Umbilical Vesicle (Yolk Sac)

Question 16

What parts of the path that sperm travel originate from the cortical cords?

Answer 16

1. Seminferous Tubules
2. Tubuli recti (straight tubules)
3. Rete Testis

(Sertoli cells also originate from the cortical cords)

Question 17

What embryonic derivative forms the epididymis and the efferent ductules?

Answer 17

Mesonephric ductules = efferent ductules

Distal part of mesonephric cord = epididymis

Question 18

What stimulates sertoli cells to secrete MIF?

Answer 18

B-hCG

Question 19

What does MIF do?

Answer 19

Blocks development of the paramesonephric duct

Question 20

What is necessary for the differentiation of the male sexual duct system and external genitalia?

Answer 20

Testosterone and androstenedione

Question 21

Leydig cells develop from….

Answer 21

Mesenchyme

Question 22

Which of the following is derived from the cortical cords?

A. Interstitial cells of Leydig
B. Primary spermatocytes
C. Seminiferous tubules
D. Spermatids
E. Spermatogonia

Answer 22

C. Seminiferous Tubules

Question 23

The ductus (vas) deferens) and epididymis are derived from the:

A. Cortical cords
B. Interstitial mesenchyme
C. Mesonephric duct
D. Mesonephric tubules
E. Ureteric bud

Answer 23

C. Mesonephric Duct

Question 24

What cells are responsible for anti-mullerian hormone?

Answer 24

Sertoli Cells

Question 25

In what stage of cell division is the female gamete of the primordial follicle found?

Answer 25

Prophase I of meiosis

Question 26

Where do the caudal ends of the paramesonephric ducts fuse and terminate on?

Answer 26

Terminate on the urogenital sinus as the uterovaginal primordium (cranial ends open into the coelmoic cavity)

Question 27

What forms the uterovaginal primordium?

Answer 27

Fusion of paramesonephric ducts

Question 28

Which cell is responsible for producing a hormone that promotes degeneration of the paramesonephric ducts?

Answer 28

Sertoli Cells

Question 29

What hormone is responsible for further development of the mesonephric ducts?

Answer 29

Testosterone

Question 30

Prostate gland develops as an epithelial outgrowth of....

Answer 30

The pelvic portion of the urogenital sinus

Question 31

What structure gives rise to the seminal vesicle?

Answer 31

Mesonephric Duct

Question 32

What structure gives rise to the prostate gland?

Answer 32

Urogenital Sinus

Question 33

Where does the upper 1/3 of the vagina develop from?

Answer 33

Paramesonephric ducts

Question 34

Where does the lower 2/3 of the vagina develop from?

Answer 34

Urogenital Sinus

Question 35

Greater vestibular glands (bartholin) are homologuous to what structure in the male?

Answer 35

Bulbourethral glands

Question 36

What is gartner's duct?

Answer 36

A part of the mesonephric duct that may be found outside of the uterus and vagina

Question 37

What structure gives rise to the uterine tubes, uterus and upper vagina?

Answer 37

Paramesonephric Duct

Question 38

What may cause a double uterus and double vagina?

Answer 38

Paramesonephric ducts fail to fuse and each develops a separate uterus

Question 39

What may cause a double uterus with a single vagina?

Answer 39

Only the distal end of paramesonephric ducts fuse

Question 40

What causes a bicornuate uterus?

Answer 40

Defective fusion of paramesonhpric ducts

Question 41

What causes a uterine septum?

Answer 41

Incomplete resorption of tissue in the developing uterus

Question 42

What is a unicornuate uterus?

Answer 42

Basically only half a uterus Only one paramesonephric duct develops

Question 43

What hormone is responsible for the trans-abdominal descent of the testicles?

Answer 43

Mullerian Inhibitory Factor

Question 44

What hormone is responsible for the movement of the testicles through the inguinal canal?

Answer 44

Testosterone

Question 45

What forms the tunica vaginalis?

Answer 45

Processus vaginalis

Question 46

What anchors the testes within the scrotum?

Answer 46

Gubernaculum

Question 47

What does the gubernaculum become in the female?

Answer 47

Ovarian ligament + round ligament of the uterus

Question 48

What structure gives rise to a congenital hydrocele?

Answer 48

Process Vaginalis (incomplete obliteration)

Question 49

Fusion of what forms the spongy urethra?

Answer 49

Urogenital folds fuse to form the spongy urethra

Question 50

What is the defect in hypospadias?

Answer 50

Failure in fusion or the urogential folds or the ectodermal cord to develop

Question 51

What is the defect in epispadias?

Answer 51

Associated with exstrophy of the bladder Faulty positioning of the genital tubercle

Question 52

What are the corpora cavernosa and corpus spongiosum developed from?

Answer 52

Mesenchyme of phallus (genital tubercle)

Question 53

What structure gives rise to the labia minora?

Answer 53

Urogenital folds

Question 54

What hormone is responsible for responsible for the clinical condition of female pseudohermaphrodism?

Answer 54

Testosterone

Question 55

What is androgen insensitivity syndrome?

Answer 55

Condition due to lack of androgen receptors 46, XY But Normal female external phenotype But possess internal testes