Development of gonads

Question 1

Name the three primordial parts of the reproductive system.

Answer 1

Gonads, Internal duct, External genitalia

Question 2

Though sex is determined at conception, the developmental stage within the first _____ weeks is termed indifferent stage.

Answer 2

first 6 intrauterine weeks

Question 3

Primordial germ cells (PGCs) from the _____ invade the urogenital ridge

Answer 3

Yolk sac

Question 4

______ and _____ cells of the urogenital ridge proliferate to form primitive sex cord

Answer 4

Epithelial and mesodermal cells

Question 5

A second set of tubes or ducts called ______ run _____ to the mesonephric duct.

Answer 5

Paramesonephric duct; lateral

Question 6

_____ ______ to the _____ forms urogenital fold.

Answer 6

Mesoderm lateral to the cloacal membrane

Question 7

The ______ end of the _______ fuses and enlarges to form genital tubercle.

Answer 7

Anterior end of the urogenital fold

Question 8

Labioscrotal swelling forms _____ to the _____ during genital development.

Answer 8

lateral to the urethral fold

Question 9

Which gene on the Y chromosome influences male gonad development?

Answer 9

SRY gene (Sex-determining Region Y)

Question 10

Indifferent gonads develop into ______ in males and ____ in females respectively.

Answer 10

Testis in males; Ovary in females

Question 11

What happens to medullary cords in male and female gonad development?

Answer 11

Develop in males; degenerate in females

Question 12

Medullary cords is also termed _____

Answer 12

Testis cords

Question 13

Cortical cords develop in _____ (male/female) gonads.

Answer 13

Females only

Question 14

Thick tunica albuginea develops in ____ (male/female)

Answer 14

Males only

Question 15

Which structure surrounds the medullary cords (testis cords) in males but not in females?

Answer 15

Tunica albuginea

Question 16

What factor on the Y chromosome propels testis development?

Answer 16

Testis-determining factor (TDF)

Question 17

Primitive sex cords develop into ______ in the testes?

Answer 17

Testis cords (Medullary cords)

Question 18

In male gonad development, ____ forms to separate the testis from the surface.

Answer 18

Tunica albuginea

Question 19

During male gonad development, primordial germ cells differentiate into _____

Answer 19

Spermatogonia

Question 20

Epithelial cells of the testis become ______.

Answer 20

Sertoli cells

Question 21

Mesenchymal cells of the testis differentiate into _____

Answer 21

Leydig cells

Question 22

Testis cords or medullary cords eventually develop into?

Answer 22

Seminiferous tubules

Question 23

Seminiferous tubules empty into the _____ (____) via ______

Answer 23

Efferent ductules (mesonephric duct) via rete testis

Question 24

____ cells produce Anti-Müllerian Hormone (AMH)

Answer 24

Sertoli cells

Question 25

Two functions of Anti-Müllerian Hormone.

Answer 25

Induces degeneration of paramesonephric duct and causes Leydig cells to produce androgens

Question 26

_____ produced by ______ enhances development of _____, ____ and ____

Answer 26

Efferent ductules, epididymis, ductus deferens

Question 27

The seminal vesicle is an outgrowth of ______; the prostate gland develops from or is a derivative of _____

Answer 27

Mesonephric duct; Urethra endoderm

Question 28

In the presence of ____, genital tubercle is further enlarged and its elongation pulls the _____ forward forming the _____

Answer 28

Androgens; urethral fold; phallus

Question 29

The fusion of ____ forms the penile urethra and its formation is completed by ______

Answer 29

Urethral folds; Recanalisation of an ectodermal plug

Question 30

The labioscrotal swelling develops into ______

Answer 30

Scrotum

Question 31

What ligamentous structure guides testis descent into the scrotum?

Answer 31

Gubernaculum

Question 32

_____ from _____ covers the gubernaculum during testicular descent from ____ to the _____

Answer 32

Processus vaginalis (from peritoneal sac); from inguinal canal to the scrotum

Question 33

In the absence of TDF, what happens to primitive sex cords?

Answer 33

They degenerate

Question 34

______ are formed in the cortex which break up into clusters surrounded by _____

Answer 34

Secondary sex cords; follicular cells

Question 35

Primordial germ cells in females form _____ arrested at _____

Answer 35

Oogonia (primary oocytes); prophase of meiosis I

Question 36

_____ ends of ____ cross anterior to mesonephric duct and fuse with the other to form _____

Answer 36

Caudal ends of the paramesonephric duct; uterovaginal canal

Question 37

Uterovaginal canal grow toward the _____ of the _____ to form the ____

Answer 37

Posterior wall of the urogenital sinus; Müllerian tubercle

Question 38

Which duct regresses in females?

Answer 38

Mesonephric duct

Question 39

Which three structures develop from the paramesonephric duct in females?

Answer 39

Uterine tube, uterus, upper 1/3 of the vagina

Question 40

The Müllerian tubercle differentiates into ______ that forms the _____

Answer 40

Sino-vaginal bulb; lower 2/3 of the vagina

Question 41

_____ part of the ______ forms the vestibule separated from the vagina by _____

Answer 41

Caudal part of the urogenital sinus; Hymen

Question 42

What does the genital tubercle become in females?

Answer 42

Clitoris

Question 43

What do the urethral folds develop into in females?

Answer 43

Labia minora

Question 44

The labioscrotal swelling in females forms _____

Answer 44

Labia majora

Question 45

Gonadal dysgenesis, female internal and external ducts is seen in?

Answer 45

Turner's syndrome (X0, non-functional Y)

Question 46

Low female hormone production leading to masculinization of external genitalia is seen in?

Answer 46

Female pseudohermaphroditism (46XX)

Question 47

External genitalia unresponsive to androgens leading to female external genitalia with undescended testes is seen in?

Answer 47

Male pseudohermaphroditism (46XY)

Question 48

What syndrome results from mutations in the androgen receptor gene?

Answer 48

Androgen Insensitivity Syndrome (AIS)

Question 49

Explain the embryologic basis of an indirect inguinal hernia.

Answer 49

Failure of processus vaginalis to close after testicular descent allows abdominal contents to herniate through the deep inguinal ring via the inguinal canal

Question 50

Name the three layers of the spermatic cord covering an indirect inguinal hernia sac.

Answer 50

Internal spermatic fascia (from transversalis fascia), Cremasteric fascia & muscle (from internal oblique), External spermatic fascia (from external oblique aponeurosis)

Question 51

The peritoneum forms which part of an inguinal hernia?

Answer 51

Hernial sac

Question 52

Testis cords develop from which embryologic structure?

Answer 52

Primitive sex cords

Question 53

Sertoli cells originate from which type of cells?

Answer 53

Epithelial cells of the primitive sex cord

Question 54

Leydig cells originate from which cells?

Answer 54

Mesenchymal cells

Question 55

The thick tunica albuginea in males surrounds which structures?

Answer 55

Medullary (testis) cords

Question 56

Mesoderm lateral to the cloacal membrane forms ______

Answer 56

Urogenital fold

Question 57

The anterior end of the urogenital fold fuses and enlarges to form ____

Answer 57

Genital tubercle

Question 58

What structure forms lateral to the urethral fold during genital development?

Answer 58

Labioscrotal swelling

Question 59

Though sex is determined at conception, the developmental stage within the first 6 intrauterine weeks is _____

Answer 59

Indifferent stage

Question 60

What structure connects the seminiferous tubules to the mesonephric duct?

Answer 60

Rete testis

Question 61

_____ is an outgrowth of mesonephric duct; _____ is a derivative of urethra endoderm

Answer 61

Seminal vesicle; Prostate gland

Question 62

Scrotum develops from _____

Answer 62

Labioscrotal swelling

Question 63

The fused caudal ends of the paramesonephric ducts form _____

Answer 63

Uterovaginal canal

Question 64

The _____ differentiates into the sino-vaginal bulb.

Answer 64

Müllerian tubercle

Question 65

_____ and _____ form the upper 1/3 and lower 2/3 of the vagina respectively

Answer 65

Mesonephric duct = upper 1/3; Sino-vaginal bulb from Müllerian tubercle = lower 2/3

Question 66

What forms clitoris, labia minora and labia majora in females?

Answer 66

Genital tubercle; Urethral fold; Labio-scrotal swelling