Intro To Reproduction And Sexual Differentiation

Front 1

How are gametes produced in sexual reproduction?

Back 1

via meiosis

Front 2

what axis regulates the endocrine function?

Back 2

hypothalmic-pituitary-gonadal axis

Front 3

what is the exocrine function of the endocrine function of the reproductive system?

Back 3

production of gametes

Front 4

what are the two roles of the reproductive system?

Back 4

endocrine function and reproductive function

Front 5

For normal gametogenesis in the gonads as well as the development and physiology of the male and female reproductive tract, what is absolutely essential?

Back 5

endocrine function of the gonads

Front 6

what are the three responsibilities of the reproductive function of the reproductive system?

Back 6

1) support gametogenesis (men= cont, women= cyclic)
2) maintenance of reproductive tract
3) maintenance of secondary sex characteristics.

Front 7

what are two endocrine glands that produce sex steroids? what type of sex steroids do they produce?

Back 7

testes (testosterone) and ovaries (estrogen)

Front 8

How do sex steroids circulate?

Back 8

bound to Sex steroid binding globulin or albumin

Front 9

how does progesterone circulate?

Back 9

bound to corticosteroid binding globulin.

Front 10

where are the sex steroids mainly metabolized? what is the half-life?

Back 10

liver; 30-60 minutes.

Front 11

what are the three androgens that will eventually be converted to testosterone?

Back 11

androstenedione, dehydroepiandrosterone (DHEA), and dihydrotestosterone (DHT)

Front 12

what cell type produces testosterone?

Back 12

leydig cells of testes

Front 13

what is required for libido in women?

Back 13

androgens

Front 14

what are the three estrogens?

Back 14

estradiol 17B, estrone, estriol

Front 15

what cells produce estrogens?

Back 15

granulosa and thecal cells of ovary

Front 16

what is responsible for producing progesterone before and during pregnancy?

Back 16

before: corpus luteum
during: placenta

Front 17

where is the Gonadotropin releasing hormone produced?

Back 17

arcuate nucleus and preoptic area of hypothalamus

Front 18

what is Gonadotropin Releasing Hormone? what is it synthesized as and then cleaved to?

Back 18

GnRH is a decapeptide that is synthesized as a preprohormone (92AA) and cleaved to a prohormone (69AA) - decapeptide

Front 19

what is the GnRH associated hormone?

Back 19

the 56AA peptide that is left after the preprohormone is cleaved to a decapeptide. Called GAP.

Front 20

T/F
the neuron secretes both GnRH and GAP into portal circulation.

Back 20

True

Front 21

where does the GnRH bind gonadotrophs?

Back 21

in the pituitary

Front 22

what does the binding of GnRH and gonadotrophs stimulate?

Back 22

release of LH and FSH in both males and females.

Front 23

what 2 other hormones share the same family as LH and FSH? what do all of these have in common? which chain confers specificity?

Back 23

TSH and hCG; all are glycoproteins with alpha and beta subunits (beta chains- specificity)

Front 24

what influences the rate of expression for genes encoding the alpha, B(lh), and B (fsh)?

Back 24

the GnRH secretion

Front 25

what are the three levels of sexual differentiation?

Back 25

Genotypic, Gonadal, and Somatic

Front 26

what are true hermaphrodites?

Back 26

individuals who have both male and female gonads

Front 27

what are pseudohermaphrodites?

Back 27

individuals with the gonads of one sex but the external genitalia of the opposite sex of both sexes.

Front 28

how long are the gonads of males and females indifferent? what 2 types of cells do they contain?

Back 28

first 5 weeks; Coelomic epithelial and Mesenchymal stromal cells

Front 29

what are the precursors of granulosa and sertoli cells?

Back 29

coelomic epithelial cells

Front 30

what are the precursors of theca and leydig cells?

Back 30

mesenchymal stromal cells

Front 31

what type of gonadal differentiation occurs in males at 6-7 weeks?

Back 31

seminiferous tubules form and sertoli cells enclose germ cells.

Front 32

what type of gonadal differentiation occurs in males at 8-9 weeks?

Back 32

leydig cells appear.

Front 33

when does female differentiation begin?

Back 33

9 weeks

Front 34

what 6 things happen when female differentiation begins?

Back 34

1) both X chromosomes become activated
2) germ cells undergo mitosis giving rise to oogonia
3) Meisosis is initiated in some oogonia
4) the oogonia that undergo meiosis are surrounded by granulosa cells and stroma
5) from stroma, theca cells develop
6) cells are arrested in late prophase.

Front 35

what is the SRY region? what does it allow for?

Back 35

the sex-determining region of Y chromosome located on the short arm of chromosome. Allows for development of testes.

Front 36

which chromosomes has genes that encode androgen receptors?

Back 36

X chromosome

Front 37

what must be present in order for the hormone to have an action on the target tissue?

Back 37

must have both androgen and its receptor

Front 38

what invades the genital ridges around 6 weeks?

Back 38

invaded by migratory germ cells.

Front 39

what 2 things are present in the early embryo regardless of sex?

Back 39

Wolffian and Mullerian duct.

Front 40

what is the wolffian duct?

Back 40

the future male internal reproductive tract

Front 41

what is the mullerian duct?

Back 41

the future female internal reproductive tract.

Front 42

what is required to actively stimulate wolffian duct formation?

Back 42

development of testes

Front 43

when are the testes distinguishable? when are they fully functional?

Back 43

distinguishable at 7 weeks gestation.
function: additional 7-9 weeks

Front 44

what are the two hormones produced by the fetal testis that are essential for male internal genitalia development? what cells produce these two hormones?

Back 44

testosterone and mullerian-inhibiting hormone or anti-mullerian hormone. Leydig cells produce testosterone, Sertoli cells produce the latter.

Front 45

T/F
Testosterone works in a autocrine fashion

Back 45

FALSE:
Paracrine

Front 46

what happens in the absence of testosterone?

Back 46

Wolffian ducts regress and Mullerian ducts become fallopian tubes, uterus, cervix, and upper 1/3 vagina.

Front 47

without 5 alpha reductase dihydrotestosterone, what cannot be stimulated to develop?

Back 47

prostate, penis, scrotum

Front 48

when does the external genitalia of both gender begin to differentiate?

Back 48

9-10 wks gestation

Front 49

The presence of what causes the genitalia to differentiate from their common linkage? what enzyme is necessary for this to be produced?

Back 49

5-alpha reductase dihydrotestosterone, dihydrotestosterone

Front 50

Name the male and female presentations for the common tissues:

1) genital tubercle
2) genital swelling
3) urethral folds
4) urogenital sinus

Back 50

1) f: clitoris; m:glans penis
2) f: labia majora; m:scrotum
3) f:labia minora; m: penile shaft
4) f: lower vagina; m: prostate gland

Front 51

what is androgen insensitivity syndrome?

Back 51

X-linked recessive defect that leads to the absence of androgen receptors on target tissues.

Front 52

How does someone with androgen insensitivity syndrome present?

Back 52

with a male genotype, but a female phenotype.

Front 53

T/F
People with androgen insensitivity syndrome cannot produce testosterone because they have undescended testes.

Back 53

FALSE:
they do have undescended testes, but they can still produce testosterone

Front 54

T/F
androgen insensitivity syndrome people are infertile, are tall, and do not have an internal tract.

Back 54

TRUE

Front 55

what is another name for androgen insensitivity syndrome?

Back 55

Morris syndrome

Front 56

if a people with AIS if XY with an active SRY region, what will happen?

Back 56

Testes will develop, but they not be able to create epididymis, vas deferens, seminal vesicles, as well as the prostate, penis or scrotum because the androgen receptors are absent on target tissues.