Development of the Genital System

Question 1

what embryonic origin is the genital system, as well as most of the urinary system

Answer 1

intermediate mesoderm

Question 2

during what week does the lateral body folding of the embryo cause the intermediate mesoderm to go retroperitoneal

Answer 2

week 4

Question 3

the intermediate mesoderm develops a bilateral urogenital ridge (urinary slightly before genital), what are the 2 portions of this ?

Answer 3

• nephrogenic cord

- gonadal ridge

Question 4

which is located more lateral to the midline, the nephrogenic cord or the gonadal ridge

Answer 4

nephrogenic cord

Question 5

what weeks are considered the indifferent stage of sexual development

Answer 5

1-6

Question 6

Which set of ducts are present during the indifferent stage of sexual development

• Mesonephric duct (Wolffian)
• paramesonephrict duct (Mullerian)
• both

Answer 6

Both are present at this time

Question 7

which genital duct gives rise to male structures and which to women ? what are the specific features ?

Answer 7

mesonephric duct ——> vas deferens

paramesonephric duct ——–> fallopian tubes

Question 8

what is another name for the mesonephric duct, how about paramesonephric duct

Answer 8

mesonephric duct = Wolffian duct

paramesonephric duct = Mullerian duct

Question 9

at what week can you notice a visible difference b/w male and female sexual development

Answer 9

week 7

Question 10

Primordial germ cells (PGC) begin migrating at week ____ and reach the gonadal ridges at week _____

Answer 10

4, 6

Question 11

what are known as the “welcoming wagons” for the primordial germ cells once they reach the gonadal ridges

Answer 11

Gonadal cord cells

Question 12

what is the embryonic origin of gonadal cord cells

Answer 12

thickened mesothelial lining cells from the gonadal ridge

Question 13

what is the SRY gene and who has it

Answer 13

sex determining region of the Y chromosome

-males

Question 14

what does the SRY gene code for

Answer 14

TDF protein

-testis-determining factor

Question 15

Testes determining factor TDF, stimulates the development of what cells from the mesenchyme of the gonadal ridge

Answer 15

Leydig cells

Question 16

what is the function of Leydig cells and who has them

Answer 16

produce testosterone, men

Question 17

what is the function of Sertoli cells, and who has them

Answer 17

caretakers of the primordial germ cells, men

Question 18

Sertoli cells develop from where

Answer 18

gonadal cord cells after they have enveloped the PGC

Question 19

when the gonadal cord cells envelope the primordial germ cells what two things form ?

Answer 19

seminiferous tubules + Rete testes

Question 20

the superior end of the mesonephric duct eventually develops into what ?

Answer 20

epidiymis

Question 21

the mesonephric tubules eventually develop into what ?

Answer 21

efferent ductules

Question 22

the production of testerone via the Leydig cells stimulates the formation of what

Answer 22

male genial ducts and external genitalia

Question 23

the caudal ends of the mesonephric duct develop into what 2 things

Answer 23

• seminal vesicles

- ejaculatory ducts

Question 24

the very caudal ends of the mesonephric duct continue to develop into the posterior wall of the urinary bladder, this are is called

Answer 24

trigone

Question 25

how do the male accessory organs, the prostate and bulbourethral gland, develop

Answer 25

endodermal outgrowths from the urogenital sinus

Question 26

what hormone do Sertoli cells produce, and what does this hormone do ?

Answer 26

Secretes Mullerian-inhibiting hormone (MIH) | -causes the paramesonephric duct (Mullerian duct) to degernerate in males

Question 27

if there is a little remnant of the Mullerian duct in males from not fully degenerating this is referred to as ?

Answer 27

appendix testis

Question 28

what week does the descent of testis start

Answer 28

week 26

Question 29

how do the testes decend

Answer 29

the gubernaculum ligament shortens which pulls down with it the testis, vas deferens, and testicular vessels

Question 30

where does the gubernaculum ligament extend to

Answer 30

from the gonad to the labioscrotal swelling

Question 31

what does the labioscrotal swelling develop into in males, females ?

Answer 31

males - scrotum | females the labia majora

Question 32

the inferior path of the testis due to the shortening of the gubernaculum ligament is eventually referred to as the

Answer 32

inguinal canal

Question 33

what are the 3 layers of the spermatic cord, and what are they derived from

Answer 33

- internal spermatic fascia (transversalis fascia) - cremaster fascia (internal oblique m.) - external spermatic fascia (external oblique m.)

Question 34

what is a hydrocoele of the testis or spermatic cord

Answer 34

fluid filled cyst w/in testis or cord

Question 35

what is a congenital inguinal hernia

Answer 35

outpouching of abdominal viscera which could lead to scrotum

Question 36

what is cryptochidism, and what causes this

Answer 36

failure of testis to descend | -lack of testosterone via Leydig cells

Question 37

what cells of the ovary develop from the mesynchyme of the gonadal cells

Answer 37

Stromal cells

Question 38

what are the equivalent caretakers of the primordial germ cells for females just like sertoli cells in males

Answer 38

follicular cells

Question 39

what causes the mesonephric duct to regress in the development of the female genital systems

Answer 39

Lack of testosterone hormones

Question 40

what causes the continued growth and development of the Mullerian duct in female genital dev.

Answer 40

lack of MIH secreted by sertoli cells

Question 41

what makes up the primordial follice in females

Answer 41

primary oocyte + follicle cell capsule

Question 42

if there are mesonephric duct remnants in the development of female genital systems, this can lead to what 3 things ?

Answer 42

- epoophoron - paraophoron - gartner duct cyst

Question 43

the cranial ends of the mullerian ducts form what

Answer 43

uterine tubes/fallopian tubes

Question 44

the caudal ends of the mullerian duct fuse together to form what ?

Answer 44

uterovaginal primordium

Question 45

what does the uterovaginal primordium develop into

Answer 45

the uterus and superior vagina

Question 46

what does the inferior vagina develop from

Answer 46

urogenital sinus

Question 47

what are sinovaginal bulbs

Answer 47

endodermal outgrowths from the urogenital sinus in females which develops into the vaginal plate which leads to the development of inferior vagina

Question 48

the accesory organs of the female genital system consist of the greater vestibular glands, urethral glands, and the paraurethral glands. These all form how

Answer 48

endodermal outgrowths from the urogenital sinus

Question 49

the descent of the ovaries uses the gubernaculum ligament just like males, how is the process different

Answer 49

when is shortens it splits in two because of the development of the uterus

Question 50

what are the derivatives of the gubernaculum ligament in females after it divides via uterus development

Answer 50

superior gubernaculum = ovarian ligament | inferior gubernaculum = round ligament of the uterus

Question 51

what does the genital tubericle develop into in males and females

Answer 51

males - glans penis | female - clit

Question 52

during development the cloacal membrane divides into what 2 folds

Answer 52

urethral fold and anal fold

Question 53

what do the urethral folds develop into in males and females

Answer 53

males - fuse to form shaft of cock | females -remain unfused as labia minor