Reproductive System Development

Question 1

WHen is genetic sex determined?

Answer 1

fertilization

Question 2

When is phenotypic sex manifested?

Answer 2

about the 7th week of development

Question 3

The SRY gene on the Y chromosomes is responsible for the production of what factor?

Answer 3

testis-determining factor

Question 4

True or false: all you need for the development of ovaries is the lack of a y chromosome

Answer 4

false - the absence of a y chromosomes will result in ovary formation, but you need two x chromosomes in order to have complete ovarian development

Question 5

Femaleness is not under hormonal influence, but estrogen is necessary for what?

Answer 5

feminization of the external genitalia

Question 6

What is the most common abnormality of sexual differentiation?

Answer 6

Kleinfelter syndrome
47,XXY
1 in 850 births!

Question 7

What is Klinefelter syndrome usually due to?

Answer 7

non-dysfunction of the XX homologues

Question 8

What is Klinefelter characterized by?

Answer 8

infertility
gynecomastia
impaired sexual maturation
atrophic testes
small penis
lack of secondary male characteristics

Question 9

What is Turner syndrome?

Answer 9

45, XO

failure of the gonads (ovaries) to develop and infantile genitalia due to the lack of paternal sex chromosome

Question 10

What characterizes Turner syndrome?

Answer 10

short stature
high arched palate
webbed neck
shield-like chest
inverted nipples
cardiac and renal anomalies

Question 11

What is ovotesticular disorder?

Answer 11

Basically true hermaphrodites - 46,XX

they possess both testicular and ovarian tissue (ovotestis)

it’s extremely rare

Question 12

Where do the gametes migrate from into the genital gonadal ridge?

Answer 12

the umbilical vesicle - yolk sac

Question 13

Aoub thow many primordial germ cells will enter the genital ridge during the latter part of the 5th week of development?

Answer 13

1000-2000

Question 14

The developing gonads consist of what three groups of cells?

Answer 14

mesothelium
mesenchyme
primordial germ cells

Question 15

In the male, the primordial germ cells migrate into what?

Answer 15

the cortical cords

Question 16

In the female, the primordial cortical cords break apart to form what?

Answer 16

the follicular cells that surround the oogonia

Question 17

What stage of development are those oogonia currently undergoing?

Answer 17

mitosis

Question 18

What do the cortical cords eventually form in the males?

Answer 18

seminiferous tubules and serve as precursors of the sustentacular cells of sertoli

also the tubuli recti (straight tubules) and rete testis

Question 19

What will develop into the efferent ductules?

Answer 19

remember - the mesonephric ductules

Question 20

What do the efferent ductules connect to in the developing fetus?

Answer 20

the mesonephric duct -the distal part of which becomes the epididymis

Question 21

What do the interstitial cells of leydig develop from?

Answer 21

mesenchyme

Question 22

Leydig cells involute after birth and reappear when?

Answer 22

at puberty

Question 23

THe sustentacular cells of sertoli don’t mature during the fetal period, but what do they produce under the influence of hCG?

Answer 23

anti-mullerian hormone

Question 24

What does the mullerian inhibitory substance do?

Answer 24

suppresses the development of the paramesopheric (mullerian) ducts, so inhibist the formation of female organs

Question 25

The follicular cells and the oogonia together form what?

Answer 25

the primordial follicles

Question 26

Under the influence of meiosis-stimulating factor, the oogonia will become what?

Answer 26

enter meiosis I and become stuck in prophase I to become primary oocytes

Question 27

The indifferent sexual duct system consists of what?

Answer 27

mesonephric (Wolffian) ducts | Paramesonephric (Mullerian) ducts

Question 28

The caudal ends of the paramesopheric ducts fuse and terminate on what? What does this form?

Answer 28

the urogenital sinus - between the ends of the mesonephric ducts as the uterovaginal primordium

Question 29

In males, what happens to the paramesonephric duct?

Answer 29

they degenerate

Question 30

What two bits are left after the paramesonephric ducts ddegenerate?

Answer 30

prostatic utricle and appendix of the testis

Question 31

Tetosterone will cause the mesonephric ducts to form what?

Answer 31

epidydmis ductus deferens ejactulatory duct

Question 32

The seminal vesicles develop as outgrowths of what?

Answer 32

the ductus deferens (mesonephric duct)

Question 33

The part of the mesonephric duct between the duct of the seminal vesicle and the urethra becomes what?

Answer 33

the ejaculatory duct

Question 34

What does the prostate gland develop as an epithelial otugrowth of?

Answer 34

the pelvic portion of the urogenital sinus intot he surrounding mesenchyme

Question 35

What does that surrounding mesenchyme form?

Answer 35

the stroma and smooth muscle of the prostate gland

Question 36

What do the bulbourethral glands develop as epithelial outgrowhts of?

Answer 36

the spongy urethra (derived from the phalic portion of the urogenital sinus)

Question 37

In the female, the absence of the anti-mullerian hormone allows the paramesonephric ducts to develop into what?

Answer 37

the uterine tubes and uterus also the upper 1/3 of the vagina and the cervix

Question 38

Where does development of the uterine tubes start?

Answer 38

develop from the cephalic, un-fused portions of the paramesonephric duct

Question 39

Where does development of hte uterus begin?

Answer 39

from the caudal fused potion of the paramesonephric ducts a the sinus tubercle.

Question 40

THe upper 1/3 of the vagina develops form the paranesonephric ducts. What about the lower 2/3?

Answer 40

urogenital sinus

Question 41

What is the female version of the bulbourethral glands?

Answer 41

the greater vestibular glands

Question 42

In females, the mesonephric ducts typically regress due to lack of testosterone, but a part may be found outside the uterus and vagina as what?

Answer 42

Gartner's duct

Question 43

What is paramesonephric duct agenesis?

Answer 43

It's complete or partial absence of the uterine tubes, uterus, cervix and vagina in females with 46,xx you still get normal development of secondary sexual characteristics vecause the ovaries are intact you have a normal ovarian cycle without a menstrual cycle

Question 44

What are some of the other odd variations of the uterus development?

Answer 44

double uterus (with double vagina or single vagina) bicoruate uterus septate uterus unicoruate uterus

Question 45

How do the testes descend?

Answer 45

through differential growth

Question 46

What hormone is responsible for the testes movement through th einguinal canal into the scrotum?

Answer 46

testosterone

Question 47

What does the processus vaginalis become in the male?

Answer 47

the tunica vaginalis

Question 48

What does the gubernaculum becom ein the female?

Answer 48

ligament of the ovary and the round ligement of the uterus

Question 49

What is the term for an undescended teste if it's in the correct path?

Answer 49

cryptorchidism

Question 50

What is the term for a testis that is located somewhere outside of the inguinal canal?

Answer 50

ectopic testis

Question 51

How does an indiret inguinal hernia occur congenitally?

Answer 51

the processus vaginalis fails to close and bowel can herniate trhoguh the deep inguinal ring

Question 52

What causes a hydrocele congenitally?

Answer 52

the tunica vaginalis has a potential space that can fill with fluid

Question 53

The genital tubercle at the cranial end of the cloacal membrane becomes what?

Answer 53

the phallus

Question 54

What are located on each side of the cloacal membrane at this point?

Answer 54

labioscrotal swelling and urogenital folds (urethral folds)

Question 55

What divides the cloacal membrane into a dorsal epithelial plug (the site of the anus) and a ventral urogenital membrane?

Answer 55

urorectal septum

Question 56

What will stimulate the phallus to enlarge and elongate into the penis?

Answer 56

testosterone

Question 57

What will fuse to form the spongy urethra in the male?

Answer 57

the urogenital folds (urethral folds)

Question 58

the line of fusion of the surface ectoderm on the vetnral surface - where the urogenital folds join -- is called what?

Answer 58

the penile raphe

Question 59

What makes the end of the urethra in the male/

Answer 59

the ectodermal cord that grows in to form the glans and connect with spongy urethra

Question 60

What layer do the corpora cavernosa and ccorpus spongiosum develop from?

Answer 60

surrounding mesenchyme of the phallus

Question 61

Labioscrotal swellings form what in the male?

Answer 61

scrotum

Question 62

What is male pseudohermaphrodism caused by?

Answer 62

reduced masculine development ofthe genitalia - maybe due to inadequate amount of testosterone or mullerian inhibiting substance

Question 63

What is male pseudohermaphrodism characterized by?

Answer 63

microphallus hypospadiasis can have bifid scrota may not have testes in the scrotum

Question 64

What is hypospadias due to?

Answer 64

failure of fusion of the urogenital folds (1 in 300) also failure of the epithelial cord to join with the spongy urethra

Question 65

What is epispadias associated with?

Answer 65

issue with lateral folding - associated with exxtrophy of the bladder

Question 66

What does the phallus become in the feamel?

Answer 66

clitoris

Question 67

The urogenital folds do not fuse in the female, but form what?

Answer 67

the labia minora

Question 68

The labioscrotal swellings form what?

Answer 68

labia majora