Female Reproductive Physiology Flashcards
1
Q
oxytocin release during ____
A
parturition (childbirth)
2
Q
LH surge that triggers ___
A
ovulation
3
Q
A
4
Q
GnRH stands for
A
Gonadotropin-Releasing Hormone
5
Q
Hypothalamic-Pituitary-Ovarian (HPO) Axis releasing factor
A
Gonadotropin-Releasing Hormone (GnRH)
*from hypothalamus
6
Q
Hypothalamic-Pituitary-Ovarian (HPO) Axis trophic hormones
A
Gonadotropins (“stimulate” gonads)
- Follicle-Stimulating Hormone (FSH)
- Luteinizing Hormone (LH)
*released from the anterior pituitary
7
Q
Hypothalamic-Pituitary-Ovarian (HPO) Axis target hormones
A
ovarian hormones - released by ovaries
- Estrogens (“generators of sexual activity”)
- Progesterone (“progestational” hormone)
- Inhibins (regulatory peptide hormones)
8
Q
key players in Hypothalamic-Pituitary-Ovarian
(HPO) Axis
A
GnRH
gonadotropins (FSH, LG)
ovarian hormones (estradiol E2, progesterone, inhibins)
9
Q
Gonadotropin-Releasing Hormone (GnRH) is released from where?
A
hypothalamus
10
Q
Gonadotropin-Releasing Hormone (GnRH) is released from the hypothalamus in response to what?
A
low E and P levels
11
Q
Gonadotropin-Releasing Hormone (GnRH) stimulates the release of what?
A
FSH and LH
12
Q
Follicle-Stimulating Hormone (FSH) is involved in follicular development and __ ___
A
steroid secretion
13
Q
Luteinizing Hormone (LH) is involved in steroid secretion and ___
A
ovulation
14
Q
Estradiol (E2) –
Progesterone –
Inhibins –
A
Estradiol (E2) – steroid hormone
Progesterone – steroid hormone
Inhibins – peptide hormones that
selectively inhibit FSH
15
Q
A
16
Q
what cells does the FSH hormone stimulate?
A
ovarian granulosa cells only
17
Q
what cells does the LH hormone stimulate?
A
ovarian granulosa cells
ovarian thecal cells
18
Q
thecal cells release what?
A
androgens
19
Q
thecal cells release androgens, that get aromatized to what? where?
A
estrogens in granulosa cells?
20
Q
____ feedback inhibits the HPO
axis
A
Estrogen
21
Q
inhibin B is released by what?
A
granulosa cells
22
Q
inhibin B hormones do what?
A
inhibit FSH secretion
23
Q
A
24
Q
A
25
During pregnancy, _____is the
predominant circulating estrogen in
terms of serum levels.
Estriol (E3)
26
After menopause, _____ is the
predominant circulating estrogen
Estrone (E1)
27
_____ is the predominant
estrogen during majority of the
reproductive years
Estradiol (E2)
28
functions of estrogens (7)
1. Female sexual maturation & development of
secondary sex characteristics
2. Increases CNS excitability (Catamenial Epilepsy)
3. Stimulate endometrial proliferation & uterine growth
4. Maintenance of healthy blood vessels & skin
5. Reduce rate of bone reabsorption.
6. Alters plasma lipids
- increases HDL & triglycerides, while decreasing LDL levels)
7. Enhances blood coagulability/blood clotting risk
29
follicular phase:
encompasses follicular development in the ovary
leading up to ovulation
1st day of menstrual cycle
30
(Days 1-5) During the follicular phase, low estrogen (E2) triggers
hypothalamic GnRH release, which stimulates the anterior pituitary to release FSH & LH
31
In the early follicular phase, _____ is released episodically at ~ 90 min intervals, resulting in pulses of ___ & ___ @ ~90 min intervals.
GnRH
FSH & LH
32
during the follicular phase, FSH & LH stimulate the growth of ’_____’ ovarian follicles into secondary follicles.
'primordial'
33
As the follicular phase proceeds, LH
secretion slowly ______ and LH
pulses get faster (~60 min intervals) increasing E2 production.
increases
34
Around Day 5-7, a small ____ in E2 inhibits FSH & LH release, “starving” follicles of FSH
increase
35
Days 7 -14: Dominant ovarian follicle
_____ E2 production as it matures
increases
36
Uterine proliferative phase: E2
stimulates (2)
endometrial growth
vascularization
37
Day 14: High [E2] levels trigger “LH
surge” which will cause a momentary switch to
_____ feedback
positive
38
LH is building up in Ant Pit leading
up to Day ____
14
39
what is key for ovulation on day 14?
LH surge !
40
What causes the LH surge?
E2 levels reach a “tipping point” threshold, BRIEFLY flipping the HPO axis from negative to positive- feedback.
41
E2 stimulates the hypothalamus to release ____ GnRH to cause LH surge
more
42
____ stimulates Ant. Pituitary to release stored LH on day 14 (“LH surge”)
GnRH
43
A rapid drop in LH & FSH returns HPO axis to a ____ feedback after “surge”
negative
44
LH surge triggers changes allowing the follicle to
rupture from ovary which is called
ovulation
45
Luteal phase begins at ____ and lasts how long?
Luteal phase begins at ovulation & lasts ~14 days
46
During the luteal phase, the remaining ovarian cells become the ______ and produce high amounts of progesterone (P).
corpus luteum
47
elevated progesterone from the corpus luteum can inhibit ____ release
gonadotropin (LH and FSH)
48
during the luteal phase, GNRH pulses slow to one pulse every ___ hrs.
4
49
when is the most fertile window?
1-2 days prior to ovulation and the day of ovulation
50
sperm appear to survive for up to __ days in the female reproductive tract
5 days
51
Progestational effects of Progesterone (changes of uterus)
Endometrial hyperplasia is inhibited,
Highly vascularized bed is created for the fertilized egg, &
Development of secretory glands is promoted (secretory phase).
52
The ovulated oocyte must be fertilized within ___ hr or it will die
24
53
If the egg is not fertilized and/or doesn’t successfully implant, the ___ ___ dies ~ 8 days after ovulation
corpus luteum
Corpus luteum becomes the Corpus albicans
54
If the egg is not fertilized and/or doesn’t successfully implant, the corpus luteum dies how many days after ovulation?
8 days after ovulation
55
56
final follicular selection & ovulation are under ____ control and thus are inhibited by hormonal contraceptives
gonadotropins
57
progestins are synthesized in the ovary, testes, & adrenal cortex from what (derivative)?
cholesterol
58
what is the most important natural progestin in humans?
Progesterone
59
While all steroid hormones are derived from cholesterol, progesterone serves as a precursor to the synthesis of all (3)
estrogens
androgens
adrenocortical steroids
60
Progestational effects (2)
Prepares the uterus for implantation of the fertilized ovum during the luteal phase of the menstrual cycle.
Plays role in the development of the secretory mechanism of the breast.
61
What increases fat deposition?
progesterone
62
what decreases CNS excitablity (anticonvulsant)?
progesterone
63
what increases body temperature (thermogenic)?
progesterone
64
what decreases PCO2 during pregnancy and in the luteal phase of the menstrual cycle?
progesterone
65
Unlike men, who make sperm throughout their lives, a female’s total supply of gametes (eggs) is determined ___
at birth
66
leptin
a satiety peptide hormone secreted by adipose cells
related to the start of puberty (body weight)
67
menarche
first menses & start of endometrial cycle
68
Ovulation does not usually begin with ___
menarche
69
The number of primordial follicles (oocytes) peaks ___ birth & then diminishes
before
70
During her reproductive years, only ~___ oocytes will be ovulated during a woman’s reproductive years (menarche to menopause).
~400 oocytes
71
”Follicular atresia”
The diminishing pool of follicles with age
72
Perimenopause varies from __-__ years preceding the onset of menopause.
1-10
73
Perimenopause: Age related decline in ___ may also contribute to loss of inhibition for FSH
inhibin B
74
Perimenopause: Menstrual cyclicity becomes irregular as __ & __ decline
estrogens (E2 & E1) and Progesterone levels
75
Menopause
the permanent cessation of menstruation caused by loss of ovarian follicular activity
76
At the onset of menopause, ___ levels are markedly elevated.
FSH
77
___ becomes the predominant circulating estrogen during menopause
Estrone (E1)
78
Most of the symptoms & disease conditions associated with menopause are primarily due to ___
estrogen deficiency
79
Unopposed ____ action on endometrium increases risk of endometrial cancer
estrogenic
80
Progesterone acts to inhibit endometrial _____
proliferation
81
Upon implantation of the blastocyst, the trophoblast cells of the early placenta begin secreting ___
human chorionic gonadotropin
(hCG)
82
during pregnancy, the corpus luteum continues to secrete _____, which in turn supports
the endometrial lining and maintains the pregnancy
Progesterone
83
human chorionic gonadotropin (hCG) bypasses the HPO axis control which does what? (2)
prompts the corpus luteum to continue
expressing P and estrogens (mainly
estriol, or E3)
prevents menstruation during
pregnancy
84
during pregnancy, uterine control is eventually taken over by the ___
developing embryo
85
86
hCG is critical because it
maintains the corpus luteum and provides protection
87
The ____ eventually takes over the production of progesterone and estrogen (3rd trimester?)
placenta
88
If other placental hormones are inadequate after hCG levels wane, then the ____ will ____ and the risk of spontaneous miscarriage increases.
endometrium will degenerate
89
Progesterone: pro-gestational effects in
pregnancy (4)
Prevents uterine contractions
Moderates maternal immune response to preserve pregnancy
Stimulates lobular-alveolar development in mammary glands
Suppressing actual milk synthesis until near childbirth
90
The principal estrogen during pregnancy
is
estriol (E3)
91
estrogen function in parturition
Estrogen: near parturition, induces uterine
oxytocin receptor expression
92
oxytocin function in parturition
causes contractions during parturition (Positive Feedback Mechanism)
induces release of placental prostaglandins which further stimulates contractions
93
relaxin function in parturition
a peptide hormone secreted by the placenta to relax the cervix & pelvic ligaments to ease childbirth.
94
Prolactin (Ant Pit) is under “___ ____ ____l” by PIF (Hypothalamus)
Predominant Inhibitory Contro
95
prolactin inhibitory factor (PIF) aka
dopamine
96
When prolactin is needed (during pregnancy & lactation), the hypothalamus stops production/secretion of ____, thus allowing the Anterior Pituitary to secrete prolactin
dopamine
97
lactation
The secretion of milk from the mammary
the gland is called lactation
98
After birth, prolactin stimulates milk
production by ____
mammary glands
99
Milk ejection is promoted by ____ in
response to suckling of the breast
oxytocin
100
negative or positive feedback: Milk ejection is promoted by oxytocin in response to suckling of the breast.
positive feedback
101
The first fluid that is released after birth is
called ___
colostrum
102
103
key points of HPO axis/ovarian cycle
104
key points of the uterine cycle
105
key points of changes throughout lifecycle of a woman
106
key points of hormonal changes that allow/promote pregnancy
107
Oral infections, such as gum disease, have been linked to ___
preterm birth.
108
dental visit tips for pregnancy:
Fetal organ development occurs during the first trimester so it is best to avoid all potential risks at this time if possible
Oral infections, such as gum disease, have been linked to preterm birth.
