Development of the Reproductive System and Pituitary Gland

Question 1

Functionally the urogenital system can be divided into what two entirely different systems?

Answer 1

The urinary and the genital system

Question 2

The urogenital system is derived from what embryonic tissue?

Answer 2

Intermediate mesoderm

Question 3

What is the urogenital ridge?

Answer 3

This is intermediate mesoderm that bulges into the intraembryonic coelmic cavity

Question 4

The urogenital ridge differentiates into what two things?

Answer 4

Nephrogenic cord/ridge and genital ridge

Question 5

Primordial germ cells originate from what?

Answer 5

Endoderm of the yolk sac

Question 6

What happens if the primordial germ cells do not migrate to or reach the genital ridge?

Answer 6

The gonads do not develop

Question 7

How are the primitive sex cords formed?

Answer 7

Epithelium proliferates and epithelial cells penetrate underlying mesenchyme

Question 8

Primitive sex cords can also be called what?

Answer 8

Gonadal cords

Question 9

During the indifferent gonad phase, both males and females have what two ductal systems?

Answer 9

Mesonephric (Wolffian) ducts and paramesonephric (Mullarian) ducts

Question 10

The Y chromosome has what gene that codes for what hormone?

Answer 10

SRY (sex determining region of the Y chromosome) gene that codes for TDF (testes determining factor) hormone

Question 11

Under influence of TDF, primitive sex cords continue to proliferate and penetrate into the medulla and form what?

Answer 11

The testes (medullary cords)

Question 12

Towards the hilum the testes cords will break up giving rise to what?

Answer 12

The tubules of the Rete Testis

Question 13

What is the tunica albuginea?

Answer 13

Fibrous connective tissue that separates the testes cords from surface epithelium

Question 14

The testes cords are composed of what two things?

Answer 14

Primitive germ cells and sustentacular cells (sertoli cells)

Question 15

What do the sustentacular (sertoli) cells secrete?

Answer 15

AMH, antimullerian hormone

Question 16

What does AMH cause?

Answer 16

The degradation of paramesonephric (mullarian) duct

Question 17

What are interstitial (Leydig) cells?

Answer 17

These are a cell population found between the testis cords

Question 18

What are interstitial (Leydig) cells derived from?

Answer 18

Mesenchyme from the genital ridge

Question 19

What do interstitial (Leydig) cells secrete?

Answer 19

Testosterone

Question 20

The testes cords remain solid until puberty forming what?

Answer 20

Seminiferous tubules

Question 21

The ductuli efferentes connects what two things?

Answer 21

Rete testis and mesonephric duct

Question 22

The ductuli efferentes will become what?

Answer 22

Ductus deferens (vas deferens)

Question 23

The genital ducts are stimulated to develop by what?

Answer 23

Testosterone

Question 24

Genital ducts in males are derived from what?

Answer 24

Mesonephric kidney system

Question 25

The mesonephric duct opens into what?

Answer 25

Into urogenital sinus on either side of the sinus tubercle

Question 26

The genital ducts in males forms what four things?

Answer 26

Epididymes, Ductus deferens, seminal vesicle, and ejaculatory duct

Question 27

Under AMH the paramesonephric duct degenerates except what part?

Answer 27

A small part of the cranial end called the appendix testes

Question 28

The testes start out intra or retroperitoneal?

Answer 28

Retroperitoneal

Question 29

What do the testes pass through as they descend into the scrotum?

Answer 29

Inguinal canal

Question 30

What is the gubernaculum?

Answer 30

This is a structure that anchors the testes to the scrotum and guides its decent

Question 31

As the testes pass through the inguinal ring it gets covered by what four things?

Answer 31

Processus vaginalis, transversalis fascia, internal abdominal oblique muscle, external abdominal oblique muscle

Question 32

What muscle does not contribute to a layer of the testes?

Answer 32

Transverse abdominus muscle

Question 33

In female development what gene is missing and therefore what hormone is not produced?

Answer 33

SRY gene is absent so no TDF is produced

Question 34

What gives rise to the cortical cords in developing females?

Answer 34

Surface epithelium continues to proliferate

Question 35

What are the follicular cells?

Answer 35

These are the cells that surround primary oocytes (oogonium)

Question 36

Why doe the mesonephric ducts degenerate and the paramesonephric ducts develop into main genital ducts in developing females?

Answer 36

A presence of estrogen and the absence of testosterone and AMH

Question 37

Paramesonephric ducts connect at the midline and the caudal tip of the combined ducts project into urogenital sinus which is up against what structure?

Answer 37

Sinus tubercle

Question 38

When the ovaries descend, the paramesonephric ducts form what 5 things?

Answer 38

Uterine tube, uterine canal, corpus uteri, cervix, upper portion of vagina

Question 39

What are the vaginal fornices?

Answer 39

Wing like expansions of vagina around the end of the uterus

Question 40

Cranial genital ligament forms what?

Answer 40

Suspensory ligament

Question 41

Caudal genital ligament forms what?

Answer 41

Ligament of the ovary and round ligament of the uterus

Question 42

What is the layer of tissue that will not be present in developing female genitalia?

Answer 42

Tunica albuginea

Question 43

What are the cloacal folds?

Answer 43

During week three mesenchyme from primitive streak migrate around cloacal membrane to form the cloacal folds

Question 44

What is the genital tubercle?

Answer 44

Folds fuse cranial to cloacal membrane to form the genital tubercle

Question 45

Caudal folds in the developing genitalia form what two things?

Answer 45

Urethral and anal folds

Question 46

The genital swellings form what in males and females?

Answer 46

Males: scrotal swellings Females: labia majora

Question 47

What is the urethral plate?

Answer 47

This is the epithelial lining of the urethral groove

Question 48

What is the penile urethra?

Answer 48

The two urethral folds close over the urethral plate and form the penile urethra

Question 49

What is the scrotal septum?

Answer 49

Line of fusion of scrotal swellings

Question 50

In females the genital tubercle elongates slightly to form what?

Answer 50

Clitoris

Question 51

In females the urethral folds do not fuse and thus form what?

Answer 51

Labia minora

Question 52

In females the urogenital groove is open and thus forms what?

Answer 52

The vestibule

Question 53

The pituitary glad is derived from what two structures?

Answer 53

Ectodermal outpocketing of stomodeum (Rathke's pouch) and downward extension of diencephalon (infundibulum)

Question 54

Adenohypophsis comes from what?

Answer 54

Cells in anterior wall of Rathke's pouch

Question 55

Pars intermedia is formed from what?

Answer 55

Posterior wall of Rathke's pouch

Question 56

The pars nervosa and stalk of the pituitary gland are derived from what?

Answer 56

Infundibulum

Question 57

The anterior lobe of the pituitary is also called what?

Answer 57

Adenohypophysis

Question 58

The posterior lobe of the pituitary is also called what?

Answer 58

Pars nervosa