Hellkatz: Female Reproductive Cycle

Question 1

What is the purpose of mitosis in oogenesis?

Answer 1

Create a larger pool of primary oocytes (46, 2N)

Question 2

What is the purpose of Meiosis in oogenesis?

Answer 2

ONE of the primary oocytes develops into a secondary oocyte (23, 2N) and is ovulated per month (ready for fertilization)

Question 3

When is the second meitotic division completed?

Answer 3

after fertilization

Question 4

What stimulates meiosis 1 and the development of primary follicles into secondary follicles?

Answer 4

LH surge

Question 5

What is recruitment?

Answer 5

During the final stage of development 6-8 follicles are recruited to get bigger, the largest wins and is ovulated while the rest undergo atresia.

Question 6

What hormones are dominant in the follicular phase?

Answer 6

estrogen (increased)

progesterone (decreased)

Question 7

What hormones are dominant in the luteal phase?

Answer 7

Increased progesterone

Question 8

What happens to the graafian follicle once ovulation occurs?

Answer 8

Graafian follicle (granulosa cells and theca cells) undergoes transformation to luteal cells and produces PROGESTERONE (key indicator of luteal phase)

*if pregnancy occurs, progesterone production increases until the placenta takes over

Question 9

What happens to the corpus luteum if pregnancy doesn’t occur?

Answer 9

CL regresses and the cycle repeats

Question 10

What is folliculogenesis?

Answer 10

The growth of primordial follicles to pre-ovulatory follicles. Follicles in develop in cohort but only one is ovulated.

Question 11

What is a primordial follicle?

Answer 11

primary oocytes surrounded by follicular cells (granulosa and theca cells)

Question 12

What are all the oogonia at birth?

Answer 12

primary oocytes (all you got for a life time!)

Question 13

What happens to primordial follicles during a lifetime?

Answer 13

Most progress to primary follicles until they’re all exhausted….that’s menopause.

Question 14

What is cyclic recruitment?

Answer 14

antral follicles that are rescued by FSH

Question 15

What is the Graafian follicle?

Answer 15

The dominant follicle is the largest and produces the most hormones and develops LH receptors. It becomes the ovulatory follicle and ruptures in response to a surge in LH.

Question 16

What promotes follicle development and LHR synthesis?

Answer 16

FSH

Question 17

What promotes estrogen synthesis?

Answer 17

FSH/LH

Question 18

Describe the normal state of the HPOA.

Answer 18

Hourly GnRH pulses>
FSH/LH basal secretion>
estrogen>
NFB on pituitary>
reduces FSH/LH secretion

Question 19

What happens to estrogen close to ovulation?

Answer 19

HIGH estrogen state that feeds bake positively

Antral follicles produce HIGH levels of estrogen>
induces rapid GnRH pulses>
increased FSH/LH

Question 20

What does inhibin do?

Answer 20

Inhibits FSH but not LH>

leading to the LH surge

Question 21

Where is GnRH produced?

Answer 21

Arcuate nucleus of the Hypothalamus

10 AA polypeptide

Question 22

What type of membrane protein does GnRH signal through?

Answer 22

Targets gonadotrophs>
Membrane G protein coupled protein Gq>
activates PLC>
DAG, IP3

Question 23

Why is the manner that GnRH is secreted important?

Answer 23

Pulsatile (can use it as a fertility treatment)

Question 24

What are the gonadotropins of the AP?

Answer 24

FSH (folliclular growth, estradiol secretion)

LH (critical for inducing ovulation, ovulation is required for formation of CL)

Question 25

What gonadotropin is targeted for contraception?

Answer 25

LH

Question 26

What gonadotropin is formed in the placenta?

Answer 26

hCG

Question 27

What maintains the corpus luteum in the first trimester keeping progesterone and estrogen levels high? What happens later in pregnancy?

Answer 27

hCG Placenta takes over steroidogenesis/pregnancy maintenance

Question 28

What distinguishes gonadotropins?

Answer 28

They're all glycoprotein hormones with identical alpha subunits but different beta subunits

Question 29

What happens to serum concentrations of gonadotropins with removal of the ovaries or menopause?

Answer 29

serum concentrations INCREASE

Question 30

What type of receptors respond to Gonadotropins?

Answer 30

Gs protein copuled

Question 31

What does LHGCR/LHR bind?

Answer 31

both LH and hCG

Question 32

What does the ovary require for steroidogenesis?

Answer 32

both LH and FSH

Question 33

What stimulates thecal cells around the follicles to produce progesterone and androgens?

Answer 33

LH

Question 34

What happens to androgens produced in thecal cells?

Answer 34

Diffuse across the basement membrane to the granulosa cell layer where FSH stimulates aromatize to convert them to estrogens (mainly estradiol 17B.

Question 35

What estrogen receptor mediates the HPO axis response to estrogen?

Answer 35

ER alpha

Question 36

Describe the ovarian cycle.

Answer 36

1. Small pulses of LH/FSH stimulate folliclular growth and secretion of ovarian steroid hormones 2. High estrogen levels increase GnRH pulses> LH surge> Ovulation 3. Ovulation induces leutinization> formation of hte corpus luteum> produces high levels of progesterone and estrogen 4. If fertilization doesn't occur> spontaneous luetolysis of corpus luteum> decrease in progesterone/estrogen levels

Question 37

What do hormonal contraceptives do?

Answer 37

Suppress LH surge

Question 38

Provokes uterine growth, predominant steroid PRIOR to ovulation

Answer 38

Estrogens

Question 39

Maintain metabolic activity in the uterus, predominant steroid AFTER ovulation

Answer 39

Progestins

Question 40

Thickens/proliferation of endometrium Development of glands from cuboidal to pseudostratified Stroma/vessel growth Tenfold increase in uterine lining

Answer 40

Estrogens

Question 41

Halts further growth of endometrium | Secretions from glands

Answer 41

Progesterone

Question 42

What leads to the maternal RECOGNITION of pregnancy?

Answer 42

chorion production of hCG that promotes the maintenance of the corpus luteum> progesterone and estradiol

Question 43

What leads to MAINTENANCE of pregnancy?

Answer 43

placenta production of hormones (hPL, inhibin, estrogen, PROGESTERONE)

Question 44

Blastocyst in uterus

Answer 44

Days 4-5

Question 45

Implantation leading to rise of hCG and maintenance of corpus luteum

Answer 45

Days 5-9

Question 46

How long does hCG maintain the corpus luteum?

Answer 46

3-4 mos until placenta becomes primary source of PROGESTERONE which is required for preg maintenance

Question 47

What is used as a pregnancy indicator?

Answer 47

Urinary hCG (esp after 1 week)

Question 48

When is the greatest likelihood of miscarriage?

Answer 48

At the end of the first trimester when transition occurs and uterine dependence shifts from ovarian to placental steroids

Question 49

What hormonal shift occurs with parturition?

Answer 49

Shift from P>E dominance to E> P dominance

Question 50

What happens during pregnancy when P>E?

Answer 50

Progesterone> 1. hyperpolarization of myometrial cells preventing contraction 2. inhibits oxytocin 3. Inhibits ER synthesis 4. Promotes storage of PG syth enzymes

Question 51

What happens during delivery when E>P?

Answer 51

1. Increase OT receptors 2. Uterine contractility 3. Uterine ripening 4. Increased PG release form placenta>myometrial contracitons 5. Oxytocin release form PP> stronger myometrial contractions

Question 52

What's responsible for mild Braxton Hicks contractions during preganncy?

Answer 52

PG (Produced in placental unit)

Question 53

What induces smooth muscle contraction and is positively autoregulated?

Answer 53

Oxytocin

Question 54

What is mammogenesis?

Answer 54

Development of epithelial duct tree (estrogen, glucocorticoids, GH dependent)

Question 55

What stimulates lobular alveolar growth?

Answer 55

progesterone | prolactin

Question 56

What happens in lactognesis I?

Answer 56

lobular alveolar growth in mid to late pregnancy

Question 57

What happens in lactogenesis II?

Answer 57

post partum onset of copious milk secretion that comes with the fall of progesterone after delivery (dependent on prolactin)

Question 58

What maintains lactation?

Answer 58

Prolactin/removal of milk

Question 59

What leads to milk ejection?

Answer 59

oxytocin

Question 60

What leads to involution?

Answer 60

lack of prolactin