Female Repro and Endo Flashcards
1
Q
Site of fertilization
A
Ampulla
2
Q
Picks up oocyte from ovary
A
Fimbria
3
Q
Portion of fallopian tube in between ampulla and uterus
A
Isthmus
4
Q
Muscular portion of uterus that allows for expulsion of fetus at birth
A
Myometrium
5
Q
Site of oocyte, estradiol, and progesterone production
A
Ovary
6
Q
Site of embryo implantation in the uterus
A
Endometrium
7
Q
Basic functions of the ovary
A
- Production of oocytes
- Secretes estradiol and progesterone
8
Q
Two endocrine glands of the ovary
A
- Follicle - contains developing oocytes
- Corpus luteum - derived from follicle after ovulation
9
Q
Germ cell(s) of the ovary
A
Oocytes
10
Q
Somatic cell(s) of the ovary
A
- Granulosa cells
- Theca cells
11
Q
Which phase are primary oocytes arrested in at birth?
A
Prophase I
12
Q
When is the first meiotic division of an oocyte completed?
A
Just prior to ovulation - then arrested in metaphase II
13
Q
When is the second meiotic division of an oocyte completed?
A
After fertilization
14
Q
Basal lamina
A
Extracellular matrix separating granulosa cells from theca cells
15
Q
Zona pellucida
A
Mucopolysaccharide layer surrounding the plasma membrane of an oocyte
16
Q
FSH stimulates production and secretion of…
A
estradiol by granulosa cells
17
Q
Theca cells express 17 alpha-hydroxylase but lack aromatase meaning…
A
They can synthesize androgens from pregnenolone but cannot convert androgens to estrogens
18
Q
Main androgen product of a theca cell
A
Androstenedione
19
Q
When does mitotic proliferation of oogonia occur?
A
Before 20 weeks of gestation
20
Q
Atresia
A
Degeneration
21
Q
How many follicles are recruited each month in a 20 yo female?
A
10-20
22
Q
How many follicles are recruited each month in a 40 yo female?
A
4-5
23
Q
Infertile range for AMH
A
0-0.8
24
Q
Low fertility range of AMH
A
0.8-2.0
25
Normal fertility range for AMH
2.0-6.0
26
AMH range that puts you at risk for PCOS
6.0+
27
Number of gametes mid-gestation
6-7 million oogonia
28
Number of gametes at birth
2 million primary oocytes
29
Number of gametes at puberty
400,000 primary oocytes
30
Number of gametes at menopause
0
31
How many oocytes are ovulated in a lifetime?
~450
32
What percent of oocytes undergo atresia in a woman's lifetime?
More than 99%
33
How long does oogenesis take to complete?
~13-50 years
34
During prophase 1, primary oocytes contain:
46 chromosomes with 2 sister chromatids
35
Follicles in the postnatal ovary contain:
Primary oocytes
36
The oocyte is separated from the granulosa cells by the:
zona pellucida
37
Theca cells in the ovarian follicle are analogous to ______ cells in the testes.
Leydig
38
_________ follicles are dependent on gonadotropin stimulation for their growth and development.
Antral
39
AMH measured in the blood serum is primarily from _______ follicles.
Small antral
40
If a patient had a 17 alpha-hydroxylase deficiency, their _____ synthesis will decrease.
- Androgen and estrogen
- NOT progesterone
41
An example of negative feedback in the regulation of ovarian function
Basal LH and FSH secretion regulating ovarian steroidogenesis
42
An example of positive feedback in the regulation of ovarian function
LH surge regulating ovulation
43
In the follicular phase is estradiol and progesterone higher?
Estradiol
44
In the luteal phase is estradiol and progesterone higher?
Progesterone
45
LH surge causes major changes in the follicle such as...
- Reinstating the meiotic division of oocytes
- Follicular prostaglandin production
- Differentiation of theca and granulosa cells into theca-lutein and granulosa-lutein cells
46
Phases of the ovarian cycle
- Follicular
- Ovulatory
- Luteal
47
Follicular phase
- Days 1-14 (length can vary)
- Cohort of follicles begin to develop
- FSH stimulates development of antral follicles and estradiol
- During day 6 one follicle becomes dominant (others undergo atresia
- Late in the follicular phase granulosa cells express LH and FSH
48
Ovulatory phase
- Day 14
- LH surge stimulates ovulation of mature follicle within 24-36 hours
49
Luteal phase
- Day 15-28 (MUST BE 14 days)
- Corpus luteum forms and then degenerates in non-pregnant women
50
Phases of the uterine cycle
- Menstrual
- Proliferative
- Secretory
51
Menstrual phase
- First day of menstruation is day 1
- Menses is discharge of blood and endometrial tissue
52
Proliferative phase
- Follows menstrual cycle
- Estradiol stimulates hyperplasia of epithelial cells
53
Secretory phase
- Follows proliferative phase
- Progesterone stimulates vascularization, glycogen production, and increased amounts of epithelial cell endoplasmic reticulum and mitochondria.
54
LH surge
- Converts follicle from estradiol to primarily progesterone secreting tissue
- Inhibin diminishes FSH surge
55
How do ovulation predictor kits work?
- Detect LH in urine
- Start testing prior to expected LH surge
- Two lines indicate LH surge
56
In the early portion of the cycle, there is minimal cervical mucus this indicates what about hormone levels?
Low estradiol and low progesterone
57
As the cycle progresses towards ovulation, cervical mucus becomes slightly more stretchable. This indicates what about hormone levels?
Estradiol is rising and there is low progesterone
58
Just before ovulation, the cervical mucus becomes thin, watery, and stretchable. What does this indicate regarding hormone levels?
High estradiol and low progesterone
59
Just after ovulation, cervical mucus thickens. What does this indicate about hormone levels?
Low estradiol and rising progesterone
60
Amenorrhea
Failure to have menstrual cycles, generally associated with failure to ovulate
61
Anovulation
Failure to ovulate
62
Primary amenorrhea
Absence of menses in a female who has NEVER ovulated
63
Example of primary amenorrhea
Turner's syndrome - A female only has one X chromosome instead of two so ovaries do not develop properly
64
Secondary amenorrhea
Cessation of menses in a female who HAS menstruated previously
65
Examples of secondary amenorrhea
- Pregnancy
- Breastfeeding
- Menopause
- Functional hypogonadism
- Poor diet
- Low body fat
- Stress
66
Endometriosis
Cyclic growth of endometrial cells in a location other than the uterus
67
Luteal phase defect
Short luteal phase (less than 14 days)
68
Describe the basic sites of oogenesis
1. Oogonium (diploid) undergo mitotic proliferation prior to birth.
2. Primary oocytes arrested in first meiotic division at birth at prophase I.
3. First meiotic division is complete prior to ovulation and arrested in meiosis II at metaphase.
4. Secondary meiotic division is completed after fertilization (haploid)
5. Mature ovum
69
Describe the roles of the three main cell types in the ovarian follicle
1. Granulosa cells: surround and nourish developing germ cells as well as hormone production.
2. Theca cells: hormone production
3. Zona pellucida: mucopolysaccharide layer separating oocyte from granulosa cells
70
Explain the difference between pre antral and antral follicles
**Pre antral follicle:**
- Theca and granulosa cells
- No antral cavity
**Antral follicle:**
- Cumulus cells
- Interna and extrerna theca cells
- Granulosa cells
- Antral cavity
71
Describe the two-cell, two-gonadotropin model of follicular steroidogenesis
Within theca cells, LH stimulates the production of androgens from pregnenolone. This is done using 17 alpha hydroxylase. In the granulosa cells, the androgens are converted into estrogen using aromatase which is stimulated by FSH.
72
Name 3 estrogens naturally synthesized by the body and indicated the major site of production
1. E1 - peripheral conversion of adrenal androgens
2. E2 - granulosa cells
3. E3 - placenta
73
Describe the changes in the follicle that occur during fetal development
By 20 weeks gestation some oogonia are surrounded by a layer of follicular cells forming primordial follicles
74
Explain why 4-5 million oogonia are lost prior to birth
Oogonia that are not incorporated into follicles degenerate prior to birth (atresia)
75
Explain what happens to follicles recruited between puberty and menopause
- Primordial follicles become pre antral follicles
- Theca and granulosa cells become capable of estrogen synthesis and secretion,
- Mature graafian follicle bulges from surface of ovary
- Follicles recruited that aren't selected for maturation undergo atresia
76
Distinguish between recruitment, development, and selection
**Recruitment**:
- At birth primordial follicles are given the signal to resume development and will either mature to ovulation or undergo atresia
**Development**:
- Primary to antral forming structures.
- Biosynthesis of estrogen
**Selection**:
- One antral follicle with one primary oocyte is selected. The mature graafian follicle bulges from the surface of the ovary as estradiol increases preparing for ovulation.
77
Describe the changes that occur to the uterine endometrium as follicular estradiol secretion rises
The uterine endometrium undergoes hyperplasia and hypertrophy. Results in trilaminar (proliferative) endometrium; thickening of extracellular matrix.
78
Describe the factors that cause the follicle to rupture and release the oocyte
Prostaglandins, collagenases, and proteases break down the wall of the ovary. Timing of ovulation is coordinated with development of oocyte. Oocyte is ovulated and resumes meiotic division.
79
Describe the status of the oocyte at the time it is ovulated
- Oocyte is ovulated and released into peritoneal cavity.
- Oocyte is surrounded by cumulus cells (granulosa) and the zona pellucida.
- Oocyte completes first meiotic division before ovulation so 1st polar body is observed as well.
80
Explain why only about 450 oocytes complete the first meiotic division and very few
complete the second meiotic division
- More than 99% undergo atresia
- Only oocytes that are selected for ovulation will undergo it division
- Only fertilized oocytes undergo 2nd division
81
Explain why Anti-Mullerian Hormone (AMH) is used clinically to assess a female’s fertility and why does it decline over a female’s lifetime?
- AMH is secreted by primary secondary (preantral) and small antral follicles which indicates how many eggs a women has.
- It declines because # of egg decline over lifetime.
82
Explain the fate of the theca and mural granulosa cells left behind after ovulation
They differentiate into luteal cells that express LH receptors LH stimulates progesterone synthesis and a little estradiol to increase the size of the corpus luteum.
83
Describe the major steroid hormone products of the corpus luteum and their regulation
by LH and FSH
LH stimulates progesterone and estradiol synthesis and secretion. Progesterone and estradiol secretion increases as the size of the corpus luteum increases.
84
Describe the changes that occur in the endometrium as a result of progesterone
secretion by the corpus luteum
Progesterone secretion increases the vascularization, glycogen content, and epithelial cell ER and Mitochondria content (more metabolically active).
85
Explain the fate of the corpus luteum in non-pregnant and pregnant females and the
roles of LH and hCG
**Non-Pregnant**:
- Corpus luteum functions for 14 days. This is due to LH (Luteotropin) stimulating the growth of the CL and steroid biosynthesis. After 14 days, Luteolysins induce luteolysis and the CL degenerates.
**Pregnant**:
- LH and hCG (released after implantation) stimulate growth of the CL and steroid biosynthesis.
86
Describe the differences between regulation of basal LH and FSH secretion by the follicle
and corpus luteum
- Basal LH secretion-regulates ovarian steroidogeneis -folicullar estradiol and luteal progesterone and estradiol (NEGATIVE FEEDBACK CYCLE)
- Estradiol inhibits LH and FSH
- Luteal progesterone and estradiol inhibit LH and FSH secretion more than estradiol alone
- Inhbin inhibits FSH
87
Explain the role of the Kiss1 neurons in the ARC and kisspeptin in negative feedback by
estradiol on gonadotropin secretion
Estradiol negatively feedbacks to kiss1 neuron bc they express estrogen receptors Kiss1 neurons send this info to GNRH neurons and pituitary which release LH and FSH to gonads
88
Consequences of menopause on gonadotropin secretion
- Menopausal women run out of follicles which produce estradiol
- Less estradiol means less negative feedback to kisspeptins which then increase GnRH which increase LH and FSH
89
Explain the role of the Kiss1 neurons in the AVPV and kisspeptin in positive feedback by
estradiol and how this leads to the LH surge
LH surge:
- sustained, elevated estradiol
- via AVPV Kiss1 neurons
- GnRH release is pulsatile (continuous exposure causes down-regulation of GnRH receptors)
- inhibin suppresses FSH and synthesis and secretion, but not LH
90
Explain why males do not get an LH surge, even if they have very high testosterone
levels
In males, the population of Kisppeptin neuron in AVPV is very small
91
Explain why elevated, sustained levels of estradiol stimulates the LH surge
Elevated, sustained levels of estradiol stimulate the LH surge through estrogen positive feedback, which triggers the hypothalamus to release a surge of luteinizing hormone (LH), ultimately leading to ovulation.
92
Explain why there is an LH surge without an equally large FSH surge
GnRH pulsatility- rapid pulses favor Lh while slower favor FSH
93
Describe the relationship between progesterone secreted by the ovary and basal body
temperature.
Basal body temperature rises after ovulation in parallel with progesterone secretion from the corpus luteum. Not a predictor because rise occurs after formation of corpus luteum.
