Reproduction 3- Female Reproduction Flashcards

1
Q

What differentiates internal from external genitalia of the female?

A

External: Lower 2/3rds of vagina and down
Internal: Upper 1/3 of vagina and above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Female internal genitalia develop from which structure?

A

Mullerian Duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the release of GnRH throughout a female lifespan

A

Low during childhood
Spikes during the nighttime during puberty (during REM sleep)–> drives secondary sex characteristic development
Consistently higher during reproductive years, and elevated during post-menopausal years (due to lack of negative feedback)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What activates the circadian release of GnRH during pubertal years?

A

Kisspeptin (both males and females)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the release of gonadotropins throughout a female’s lifetime

A

LH and FSH both surge during fetal and infancy
Low during childhood
Surge with menstruation
High as postmenopausal due to lack of negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the menstrual rhythm?

A

HPG axis feedback mechanisms that generate a cyclical monthly pattern of hormone secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

GnRH stimulates the release of what from where?

A

GnRH stimulates release of FSH and LH from the anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

FSH primarily stimulates what type of cell?

A

Granulosa cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

LH primarily stimulates what type of cell?

A

Theca cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Inhibins are produced what which cells in the female gonad? What is its role?

A

Inhibins are produced by granulosa cells and inhibit FSH release from the anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Granulosa cells produce which two hormones?

A

Estrogens (from androgens produced by theca cells)

Progestins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

LH binds to what cells in the female gonad?

A

Theca cells and granulosa cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Theca cells produce what hormones?

A

Androgens (converted to estrogens in granulosa cells)

Progestins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

FSH stimulates the development of what?

A

The follical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

LH regulates what?

A

ovulation and leutinization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Discuss the ration of FSH to LH throughout a female lifespan

A

FSH is always greater than LH EXCEPT during reproductive years-

During reproductive years, LH > FSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Discuss the negative and positive feedback effects of estrogen

A

Estrogen has negative feedback mechanisms normally, but has positive feedback mechanisms during times of ovulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is defined as day 1 of the menstrual cycle?

A

The first day of menses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the three phases of the ovarian cycle?

A

1) Follicular phase- growth of dominant follicle
2) Ovulatory phase- follicle rupture and release of oocyte
3) Luteal phase- formation of corpus luteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which is the most variable phase of the ovarian cycle?

A

The follicular phase

Can vary from 10-14 days in woman to women or from month to month of the same woman

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the three phases of the endometrial cycle?

A

1) Menstrual phase
2) Proliferation phase
3) Secretory phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How are the ovarian and endometrial cycles coordinated?

A

The HPG axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a Graafian follicle?

A

Mature follicle at the end of the follicular phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

WHen do the primordial follicles reach their peak numbers?

A

20 weeks of gestation.

Only 10% remain at puberty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Of the 300,000 primordial follicles that survive to menarche, how many will mature into a dominant follicle?
450
26
Describe the structure of the primordial follicle (the oocyte arrested in the diplotene stage of prophase)
Outer layer of pre-granulosa cells + small oocyte No theca cells
27
Describe the structure of the primary follicle
Larger oocyte surrounded by cuboidal granulosa cells.
28
What hormone signaling is required for a primordial follicle to develop into a primary follicle?
FSH stimulation. This happens during puberty when you start to get spikes of FSH
29
At what stage of oocyte development do you start to see thecal cells?
Secondary follicles
30
Describe the secondary follicles
Differentiation of stromal cells to theca cells, multilayered granulosa cells, enlargement of the oocyte
31
Granulosa cells of the tertiary follicle secrete fluid to create what?
Antrum
32
Granulosa cells closest to the oocyte secrete mucopolysaccharides to create what structure?
Zona pellucida- must be penetrated by the sperm to get to the oocyte (hence the hydrolyzing enzymes)
33
How is a dominant follicle determined?
Dominant follicle is determined based on sensitivity to FSH and actions of AMH produced by granulosa cells THe more FSH receptors a cell has, the more likely it is to become the dominant follicle. The rest die..
34
What is atresia?
The process by which the non-dominant follicles degenerate and are subsequently reabsorbed during the follicular phase of each menstrual cycle
35
What are the three subtypes of granulosa cells that develop in a dominant follicle?
Mural cells Cumulus cells Antral cells
36
What are the mural cells?
Granulosa cells farthest from the oocyte. They have lots of LH receptors and are very metabolically active
37
What are the cumulus cells?
cells near the oocyte. They are shed at ovulation
38
What are the antral cells?
Face the antrum. They form the luteal cells after ovulation
39
Why is FSH high at the end of the ovarian cycle?
High FSH recruits a new cohort of follicles to enter the follicular phase.
40
What do follicles recruited to the follicular phase produce inhibin B?
Inhibin B negatively inhibits more FSH production to stop recruitment of new primordial follicles to maturation, and ensures that only the most sensitive follicle survives.
41
Why is it important that LH is higher than FSH during the reproductive years?
This allows for increased steroidogenesis in the theca cells
42
What is the impact of inhibin B on the gonads?
Positively paracrine on theca cells- augments steroidogenesis
43
Growing follicles produce a lot of E2. How does the E2 feedback affect the LH/FSH ratio?
E2 feedback favors LH over FSH production (high frequency, low amplitude GnRH pulses) This acts at the ovary to stimulate steroidogenesis
44
Describe the steps leading up to estrogen synthesis in granulosa cells
LH binds to LH receptors on theca cells. This stimulates the synthesis of androstenedione (weak androgen) Androstenedione diffuses through the blood into the nearby granulosa cells. FSH binding to granulosa cells stimulates the production of CYP19 (gene for aromatase) which leads to the upregulation of conversion of androgens to estrogen
45
What is the LH surge?
Switch from negative feedback of E2 on hypothalamus to positive feedback. Mechanism unknown. Surge in GnRH leads to surge in LH. THis causes the oocyte to complete meiosis I and enter meiosis II Positive feedback continues until ovulation
46
How does E2 affect the number of PRs?
E2 increases the number of PRs
47
How long does the ovulatory stage last?
1-3 days
48
What is the corona radiata?
The "cloud" of cumulus cells surrounding the oocyte
49
What is the corpus luteum?
remnant follicle
50
What is the major hormone product of the luteal phase?
Progesterone (E2 is low) Progesterone is really important for preparing the endometrium for implantation
51
Corpus luteum produces which form of inhibin?
Inhibin A- which does NOT inhibit FSH production
52
How does FSH affect E2 concentrations?
FSH increases aromatase expression and therefore leads to increased conversion of androgens to E2
53
Which cells expand to form the corona radiata cumulus oophorus?
Cumulus cells
54
Oocytes complete meiosis I and then arrests in what phase?
Metaphase in meiosis II --> now a secondary oocyte and a polar body
55
What is ovulation?
The rupture of the follicle and release of the oocyte into the peritoneal cavity. This is done by proteolysis of basement membrane
56
In the ruptured Graafian follicle, the granulosa and theca cells remain in the follicular cavity. What happens to this structure?
It reorganizes into the corpus luteum
57
How do E2 and LH regulate one another during an LH surge?
Increased LH leads to more E2; more E2 leads to more LH...positive feedback
58
How does ovulation stop the LH surge positive feedback with E2?
Rupture of the follicle causes a decrease in E2. Loss of E2 positive feedback leads to a decrease in LH to new plateau
59
The corpus luteum becomes the new endocrine unit formed from the ruptured follicle. What hormones are produced?
Progesterone (to maintain pregnancy) It also secretes gonadal steroids that optimize implantation and maintain the potential zygote
60
Loss of LH will cause the corpus luteum to degrade unless it is "rescued" by what?
hCG- the equivalent hormone secreted by implantation of a fertilized embryo.
61
What is the functional zone of the uterus?
The functional zone is comprised of the cells that are shed during menstruation
62
Uterine glands secrete what?
substances for embryo survival
63
What happens when blood flow to the spiral arteries is reduced?
Ischemia --> necrosis of the endometrial layer
64
Describe the levels of E2 and progesterone during menses
E2 and progesterone are low because of the regression of the corpus luteum and because the new follicles are immature.
65
What happens to FSH during menses?
FSH rises due to lack of negative feedback
66
What is the primary driver of the proliferative phase?
E2.
67
What is being secreted during the secretory phase of the uterine cycle?
large amounts of carbohydrate-rich mucous.
68
What is predecidualization important for?
Development of placenta if pregnancy occurs
69
What inhibits the overgrowth of the endometrium?
Progesterone- progesterone antagonizes the proliferative effects of E2
70
Why doesn't menstrual blood clot?
High levels of fibrolysins
71
What happens to the cervical mucus during the follicular phase?
Cervical mucus increases, becomes more alkaline and less viscous
72
What is Spinnbarkeit and Ferning?
They are terms that characterize ovulatory mucus Spinnbarkeit refers to stretchable mucus Fernin- the pattern when dried on a glass slide