Female Reproductive Function

Question 1

what are the three phases of the ovarian cycle?

Answer 1

follicular, ovulatory and luteal

Question 2

what are the two functions of the ovaries?

Answer 2

to produce ova and hormones

Question 3

describe the follicular phase and trigger.

Answer 3

FSH stimulates development of follicles

Question 4

describe the ovulatory phase and trigger

Answer 4

LH surge causes rupture of one of the follicles

Question 5

describe the luteal phase

Answer 5

LH converts the ruptured follicle to the corpus luteum

Question 6

what happens to the corpus luteum if fertilization does not occur?

Answer 6

it degenerates into a corpus albicans

Question 7

what do primordial follicles consist of and when are they developed?

Answer 7

they contain a primary oocyte and are formed by 6 months of age

Question 8

what three cells are contained within a follicle?

Answer 8

ovum, thecal and granulosa cells

Question 9

what is the final stage of a follicle before release?

Answer 9

the graafian follicle

Question 10

what are the three phases of the endometrium?

Answer 10

proliferative, secretory and menstrual

Question 11

what does estradiol do to the endometrium and what ovulatory phase does this correspond with?

Answer 11

promotes proliferative phase of the endometrium increasing thickness
follicular phase

Question 12

what phase corresponds with the variability of menstrual cycle length?

Answer 12

the proliferative phase can vary in length

Question 13

what does progesterone do in the uterus and what ovulatory phase does this correspond with?

Answer 13

triggers the secretory phase

luteal phase

Question 14

what is the secretory phase in the endometrium?

Answer 14

accumulation of glycogen, increased glandular secretion and increased vascularity in the endometrium

Question 15

what mediates the menstrual phase? describe it.

Answer 15

prostaglandin

vasoconstriction of arteries causes local ischemia

Question 16

what part of the ovarian cycle corresponds with the menstrual phase?

Answer 16

regression of the corpus luteum

Question 17

describe the positive feedback on the ovarian cycle.

Answer 17

estradiol reaches high levels in late follicular phase causing LH and FSH release

Question 18

describe the negative feedback on the ovarian cycle.

Answer 18

early follicular phase: estrogen has negative feedback

luteal phase: estradiol, progesterone and inhibin produced by the corpus luteum decrease gonadotropin release

Question 19

which axis is responsible for the ovarian cycle?

Answer 19

the hypothalamic-pituitary- ovarian axis

GnRH-> LH and FSH-> androgen, progestin andestrogens

Question 20

describe the characteristics of the release of GnRH and LH

Answer 20

they are pulsatile and increase in amplitude during the follicular phase

Question 21

what causes the increase in amplitude of LH in the follicular phase?

Answer 21

high circulating estrogen sensitizes the gonadotrophs of the anterior pituitary to stimulation by GnRH

Question 22

where is GnRH secreted?

Answer 22

from small neurons in the arcuate nucleus and preoptic area of the hypothalamus

Question 23

what are the two effects of GnRH?

Answer 23

to increase secretion of FSH in the follicular phase and LH during the luteal phase

Question 24

what cells does FSH bind to and what does it cause?

Answer 24

granulosa cells

stimulates transcription of enzymes, activins and inhibins

Question 25

what cells does LH bind to and what does it cause?

Answer 25

``` theca cells (granulosa cells also have receptors) stimulates synthesis of progestins and androgens ```

Question 26

what do granulosa cells do to androgens secreted by theca cells?

Answer 26

they turn them into estrogens

Question 27

where do actins and inhibins act? what do they do?

Answer 27

on the anterior pituitary | activate/inhibit gonadotropin release

Question 28

where do estrogens and progestins work as feedback?

Answer 28

on both the hypothalamus and the anterior pituitary

Question 29

describe the signaling pathway of GnRH

Answer 29

binds to GPCR and triggers the IP3/DAG signaling pathway DAG->PKC-> gene transcription alteration IP3-> intracellular calcium release-> exocytosis of gonadotropin

Question 30

what types of hormones are estradiol and progesterone? how do they travel in the blood?

Answer 30

steroid hormones | bound to sex hormone binding globulins

Question 31

what 6 tissues do female gonadotropins act upon?

Answer 31

breast, bone, vagina, cervix, fallopian tubes and uterus

Question 32

how are estrogen and progesterone removed from the body?

Answer 32

estrogen: inactivated in liver by conjugation and excreted in urine progesterone: degraded to other steroids in liver and urinated

Question 33

what are the major products of the follicle and corpus luteum?

Answer 33

estradiol (follicle) and progestins (corpus luteum) although there is still estradiol production

Question 34

what enzyme does the theca cell lack?

Answer 34

aromatase

Question 35

what hormone promotes the conversion of cholesterol to androstenedione? the conversion of androstenedione to estradiol?

Answer 35

LH | FSH

Question 36

which cells produce progesterone?

Answer 36

both granulosa and theca cells

Question 37

which cell converts progesterone to 17alpha-OH progesterone?

Answer 37

theca cell (granulosa cell does not contain the enzyme)

Question 38

what are 4 effects of estrogens?

Answer 38

proliferation of the uterus and development of endometrial glands, development of fallopian tube mucosa, stimulation of bone growth by inhibiting osteoclasts, and increase subcutaneous fat deposition

Question 39

what are three effects of progesterone?

Answer 39

secretory changes in uterine endometrium, decreasing uterine contractions and increased fallopian tube secretions

Question 40

what is thelarche? what are the roles of estrogen and progesterone?

Answer 40

when breast development occurs estrogens- deposition of fat, stromal tissue development and ductile growth in breasts progesterone- promotes development of lobules and alveoli

Question 41

what is adrenarche?

Answer 41

increased secretion of adrenal androgens

Question 42

what is menarche?

Answer 42

when the menstrual cycles begin

Question 43

what about the hypothalamus-pituitary-ovarian axis changes at puberty? what causes the development of secondary sex characteristics?

Answer 43

the link that activates the hypothalamus pulsatile secretion of GnRH occurs at the beginning production of steroid hormones causes transition

Question 44

what inhibits the release of gonadotropins before puberty?

Answer 44

the negative feedback sensitivity is high so low levels of steroid hormones block gonadotropin release

Question 45

what is the average age of menopause? how many ovarian follicles are left?

Answer 45

51 | virtually none

Question 46

describe the levels of sex steroids and gonadotrophins in menopause.

Answer 46

sex steroid levels decrease and gonadotrophins increase

Question 47

what physical and mental changes occur in menopause?

Answer 47

vasomotor instibility, hot flashes, night sweats, mood changes, short term memory loss, sleep disturbance, lack of libedo and headaches

Question 48

what physical changes occur to the female reproductive system in menopause?

Answer 48

atrophy of vaginal epithelium, changes in pH, decrease in secretions, loss of tone, decrease in circulation to vagina and uterus and pelvic relaxation

Question 49

how does the amount of germ cells in a fetus compare to the follicle number at birth?

Answer 49

about 4 times the amount as a fetus compared to at birth

Question 50

how many oocytes are ovulated during a lifetime? how many follicles are there at puberty?

Answer 50

about 400 | 400,000

Question 51

what causes the decrease in steroid hormone production in menopausal women? how does this effect gonadotropins?

Answer 51

there are no more follicles to produce it | there is no more negative feedback so gonadotropin levels rise

Question 52

what causes most of the loss of follicle?

Answer 52

atresia of cells throughout the reproductive lifetime

Question 53

how can a woman's menopausal status be determined?

Answer 53

with immunoassays of FSH and LH (10-20x more production in menopause)

Question 54

what is the postmenopausal source of estrogens? how do they compare to estradiol?

Answer 54

muscle and adipose tissue produce esterone derived from androstenedione from the adrenal gland and ovary 15-25% as potent as estradiol

Question 55

what accounts for the severity of menopausal symptoms?

Answer 55

amount of esterone produced in other tissues because symptoms are a result of estrogen deficiency

Question 56

why are postmenopausal women more prone to fracture?

Answer 56

because estrogen preserves bone mass