Physio: Reproductive Physiology - Female Reproduction

Front 1

What are the 2 main functions of the ovaries?

Back 1

oogenesis, secretion of female sex steroid hormones (estrogen and progesterone)

Front 2

What is the functional unit of the ovary?

Back 2

single ovarian follicle (one germ cell surrounded by endocrine cells)

Front 3

At birth, the majority of germ cells are in what stage?

Back 3

primary oocytes, in prophase of meiosis I
(ALL oogonia will be in this stage by 6months post partum)

Front 4

What are the developmental steps that occur in the transformation of primordial germ cells to primary oocytes?

Back 4

primordial germ cell -> mitosis -> oogonia -> enter prophase of meiosis I -> primary oocyte

Front 5

What are the stages in the development of primordial ovarian follicles to mature follicle?

Back 5

primordial ovarian follicle -> primary follicle (remains until puberty) -> secondary follicle (few follicle enter each menstrual cycle) -> graafian follicle (presence of antrum) -> ovulation!

Front 6

When is the oocyte's first meiotic division completed?

Back 6

upon ovulation (and begins 2nd division)

Front 7

When is the 2nd meiotic division completed?

Back 7

upon fertilization

Front 8

What does the corpus luteum become if there is no fertilization?

Back 8

corpus albicans

Front 9

Why can't theca cells produce estradiol?

Back 9

they contain cholesterol desmolase (stim by LH), thus can produce testosterone, but no aromatase

Front 10

How is estradiol produced in the ovaries?

Back 10

testosterone from theca cells diffuses to granulosa cells and is converted to 17beta-estradiol by aromatase (stim by FSH)

Front 11

What type of feedback mechanism dominates the follicular phase?

Back 11

LH and FSH stimulate estradiol secretion by follicular cells, which exerts NEGATIVE feeback on a/p to inhibit FSH/LH

Front 12

What type of feedback mechanism dominates at midcycle?

Back 12

when critical level of estradiol is reached, exerts POSITIVE feedback on a/p to cause LH/FSH surge

Front 13

What type of feedback mechanism dominates the luteal phase?

Back 13

progesterone secreted by ovaries exerts NEGATIVE feedback on a/p to inhibit LH/FSH s/c

Front 14

What hormone is responsible for maturation and maintenance of uterus, fallopian tubes, cervix, and vagina?

Back 14

estrogen

Front 15

What hormone is responsible for development of secondary sex characteristics at puberty?

Back 15

estrogen

Front 16

What hormone is responsible for developement of breasts?

Back 16

estrogen and progesterone

Front 17

What hormone is responsible for maintenance of pregnancy?

Back 17

estrogen and progesterone

Front 18

What hormone is responsible for proliferation and development of ovarian granulosa cells?

Back 18

estrogen

Front 19

What hormone maintains secretory activity of uterus during luteal phase?

Back 19

progesterone

Front 20

What hormone is responsible for upregulation of estrogen, progesterone, and LH receptors?

Back 20

estrogen

Front 21

What type of feedback (neg or pos) does estrogen have on LH and FSH?

Back 21

negative during follicular and luteal phases, positive during ovulation

Front 22

What hormone raises uterine threshold to contractile stimuli during pregnancy?

Back 22

progesterone (preserving pregnancy until fetus is ready to be delivered)

Front 23

What hormone lowers uterine threshold to contractile stimuli during pregnancy?

Back 23

estrogen

Front 24

What hormone stimulates prolactin secretion (but then blocks its action on the breast)?

Back 24

estrogen

Front 25

What type of feedback (neg or pos) does progesterone have on LH and FSH?

Back 25

negative, during luteal phase

Front 26

What effects does estradiol have on the endometrial lining during the proliferative phase?

Back 26

stimulates growth of endometrium, growth of glands and stroma, elongation of spiral arteries, causes cervical mucus to become copious, watery, elastic

Front 27

Where are estrogen and progesterone synthesized during pregnancy?

Back 27

first trimester: by corpus luteum
2nd,3rd: by placenta

Front 28

What hormone affects body temperature during what part of the menstrual cycle?

Back 28

progesterone raises body temp during luteal phase

Front 29

What days are landmarks in the menstrual cycle?

Back 29

day 1 = onset of menses from previous cycle
~day 15 (but can range from day 8 to day 22) = ovulation

luteal phase = 14 DAYS (ALWAYS CONSTANT)

*ovulation always occurs 14 days prior to menses*

Front 30

What are the follicular changes during the proliferative phase?

Back 30

one graafian follicle becomes the dominant follicle after neighboring follicles become atretic (degenerate)

Front 31

What are the hormonal changes during the follicular phase, and what are the stimulatory factors?

Back 31

receptors for FSH and LH (and estrogen) are up-regulated in ovarian theca and granulosa cells, gonadotropins stimulate synthesis of estradiol

Front 32

What are the EFFECTS of the hormonal changes that occur during the follicular phase?

Back 32

high estradiol causes:
1.proliferation of endometrial lining (which was recently shed)
2. neg feedback inhibition of LH and FSH from a/p

Front 33

What event initiates ovulation?

Back 33

estradiol levels pass threshold, exert positive feedback on LH, cause LH and FSH surge

Front 34

What changes occur in the cervical mucus at ovulation?

Back 34

cervical mucus increases in quantity and becomes more watery and penetrable by sperm

Front 35

What happens to the follicle after ovulation?

Back 35

becomes corpus luteum (theca-lutein and granulosa-lutein cells)

Front 36

What hormones do the cells of the corpus luteum produce?

Back 36

theca lutein cells produce adronstenedione (stim by LH), granulosa lutein cells (stim by FSH) produce estradiol (from androstenedione) and progesterone

Front 37

What is the dominant hormone during the secretory phase?

Back 37

progesterone

Front 38

What are the effects of progesterone in the early-mid secretory phase?

Back 38

increased vascularization and secretory activity of endometrium, in preparation to receive fertilized ovum, basal body temp increases, and (w/estrogen) NEG FEEDBACK INHIBITION OF LH and FSH

Front 39

What occurs hormonal changes occur in the late luteal phase, and what event precipitates these changes?

Back 39

-low LH causes dec production of estrogen/progest by corpus luteum
-unless rescued by hCG, corpus luteum degenerates to corpus albicus and leads to decreased progesterone and estrogen

Front 40

What is the result of these hormonal changes in the late luteal phase?

Back 40

low estrogen/progest = diminished neg feedback inhibition of FSH/LH, so gonadotropin secretion begins to rise again