Female Reproductive Physiology

Question 1

What are the main components of the female reproductive system

Answer 1

uterus, fallopian tube, ovary

Question 2

What is the main difference between males and females when it comes to sex cell formation in fetal development

Answer 2

in males mitosis continues throughout out adulthood-always have production of new sperm cell cells because the spermatogonia that doesn’t go through meiosis continues to divide
in females, mitosis only occurs in embryonic life- the primary oocyte at meiosis 1 will stop and resume at meiosis 2 only if it selected after puberty

Question 3

Oocytes

Answer 3

these are also known as eggs. the female sex cells

Question 4

How are oocytes produced?

Answer 4

During fetal development, the primordial germ cells will go through mitosis many times- oogonia (the end result of mitosis)
2. oogonia will enter meiosis 1, duplicate their DNA and stop- at birth females have their primary oocytes
3. After puberty one primary oocyte completes meiosis 1 and enters meiosis 2 to become secondary oocyte every 28 days
4. the secondary oocyte will only complete meiosis 2 if the oocyte is fertilized.

Question 5

What happens if the oocyte is not fertilized?

Answer 5

it will die 12-24 hours after ovulation

Question 6

What is the outline of oocyte maturation

Answer 6

primary follicles surround the oocytes and every 28 days 5-10 follicles are recruited but only one will move to full maturation

1. primary follicle
2. secondary follicle
3. early tertiary follicle
4. dominant follicle
5. the follicle will rupture releasing the oocyte

Question 7

What happens to the oocytes that do not reach full maturation

Answer 7

they undergo atresia- hormonally regulated cell death

Question 8

Role of Granulosa cells

Answer 8

immediately surround the oocyte and helps with its development

Question 9

Role of Theca Cells

Answer 9

secrete steroid hormone precursor

Question 10

what are the components of the menstrual cycle?

Answer 10

ovarian and uterine cycles

Question 11

What 2 phases make up the ovarian phase?

Answer 11

Follicular phase and luteal phase

Question 12

Steps in the ovarian cycle

Answer 12

1. small number of primordial follicles develop
2. becomes a primary follicle with theca and granuloma cells. theca cells synthesize androgens which are converted into estrogens in granulosa cells
3. some follicles develop to secondary follicles
4. Structure becomes tertiary follicle
5. dominant follicle (Graafian) develops
6. Graafian follicle ruptures releasing oocyte and ovulation begins
7. the oocyte will jump to the fallopian tube and Cumbria will capture oocyte and move it to uterus
8. the follicular cells left behind will become corpus luteum- which releases progesterone and estrogen
9. if fertilization does not occur, corpus luteum degenerates

if fertilization occurs, the corpus luteum continues to make progesterone and estrogen until the end of the first trimester

Question 13

What is the scar tissue of the degenerated corpus luteum called?

Answer 13

corpus albicans

Question 14

What is the LH surge? when does this happen?

Answer 14

the LH surge occurs during the follicular stage when the follicular cells release collagenase (digest the connective tissuee at the end of the ovary) and progesterone (facilitate expulsion of oocyte by causing smooth muscle contraction)

Question 15

Luteal phase

Answer 15

the ruptured follicle will turn into corpus luteum and will regress- its fate will depend on whether the oocyte becomes fertilized

Question 16

when does the ovarian cycle occur?

Answer 16

during days 14-28

Question 17

Uterine Cycle

Answer 17

blood vessels in the endometrium undergo constriction that causes shedding of the endometrial lining

Question 18

Endometrium

Answer 18

inner lining of the uterus that contains blood vessels

Question 19

Why does the inner lining of the endometrium shed?

Answer 19

due to declining levels of progesterone and estrogen, which are signs of no fertilization

no fertilization means that the thickened part of the endometrium is no longer needed

Question 20

What is the proliferative phase of the uterine cycle

Answer 20

this is where the endometrium develops in response to estrogen. the endometrial lining thickens as blood supply to tissues is re-established

Question 21

what is the secretory phase of the uterine cycle

Answer 21

glands in the endometrium secret viscous fluid. endometrial cells deposit lipid and glycogen in cytoplasm under the influence of progesterone and estrogen

Question 22

what are the three phases of the uterine cycle

Answer 22

1. menstrual phase
2. proliferative phase
3. secretory phase

Question 23

how are the ovarian and uterine cycles integrated and overlap

Answer 23

1. when the follicle is growing so does the endometrium
2. as we enter the luteal phase of ovarian cycle, the endometrium continues to expand and thicken in preparation for a fetus
3. if there is no fertilization, corpus albican signals to the endometrium to start shedding because there is no

Question 24

what are the estrogen and progesterone levels during the follicular, menses and proliferative phases

Answer 24

in this phase, this is where the follicle is growing, so estrogen is triggered but progesterone stays low

Question 25

what are the estrogen and progesterone levels during the luteal and secretory phase

Answer 25

at the end of the follicular phase estrogen drops and progesterone starts to spike due to the corpus luteum as a way to help the potential fetus

estrogen also starts to see a slight increase from the corpus luteum

Question 26

how is the menstrual cycle regulated?

Answer 26

by GnRH, FSH, and LH

Question 27

how is the role of LH different between males and females

Answer 27

in males it is only FSH that contributes to gamete production, however in females LH and FSH contribute to gamete production

Question 28

What hormones are impacted or triggered during the early follicular/ menses phase

Answer 28

gonad hormone levels: both FSH and LH levels are low
there are some follicular formation
ovarian hormone levels: estrogen is high and inhibin and progesterone is low
uterine cycle: menstruation and shedding of endometrium

Question 29

what exactly is happening during the early follicular/menses phase?

Answer 29

LH stimulates the release of androgens from the theca cells

FSH converts estrogen from granulosa cells

granulosa cells secrete AMH to prevent the recruitment of additional follicles

estrogen exerts positive feedback on granulosa cells, increasing proliferation and estrogen

estrogen exerts negative feedback on hypothalamus/pituitary- which shuts down FSH and LH

Question 30

in the early follicular phase, why would is the negative control on FSH and LH not a bad thing?

Answer 30

because the granulosa cells are able to produce their own estrogen at this point

Question 31

What exactly happens during the late follicular/proliferative phase?
(Day 5-14)

Answer 31

Tertiary follicle is present

follicular cells secrete inhibin, estrogen, and progesterone

inhibin inhibits FSH because we don’t really need it

progesterone increases pituitary sensitivity to GnRH- which increases LH levels

High estrogen increases frequency of LH

In this phase we experience an LH surge that triggers the completion of meiosis 1 and ovulation

Question 32

hormones impacted by the late follicular phase/ proliferation

Answer 32

LH: strong increase
GnRH: High increase
estrogen and progesterone: increase
inhibin: increase
FSH: decreased

Question 33

What happens during the early to mid luteal phase

Answer 33

after day 14, LH drops

Progesterone, estrogen, and inhibin increases

negative feedback of the previous hormones on hypothalamus and GnRH

Question 34

What happens during late luteal phase

Answer 34

corpus luteum undergoes apoptosis if egg not fertilized

progesterone and estrogen levels fall

GnRH and hypothalamus activity begins again and LH and FSH release

Question 35

what is menopause

Answer 35

the ovaries are unable to respond to LH or FSH

estradiol and progesterone levels fall

lack of negative feedback causes FSH and LH to rise

Question 36

how do birth control pills work to prevent pregnancy

Answer 36

they contain both progesterone and estrogen which when increased in the body, will cause negative regulation of GnRH and hypothalamus which will inhibit FSH and LH, preventing follicular maturation