Repro Physiology Flashcards
The α subunit is similar in what 4 hormones, giving them abilities to stimulate some of each other’s hormonal properties?
β-hCG, TSH, FSH, & LH
Where is β-hCG produced?
A small amount may be produced by the anterior pituitary but the majority comes from the placenta
(thus any more than a minimal amount of β-hCG is indicative of pregnancy)
Where is Progesterone synthesized?
Ovarian tissues: including granulosa, theca and luteal cells
(in a process stimulated by LH and FSH)
In women, androgen is made where?
Androgen is made by follicular theca cells
& by luteinized theca cells
Do the ovaries produce glucocorticoids?
No.
The ovary does not have 21 deoxyhydrogenase or 11 beta dehydrogenase therefore cannot synthesize glucocorticoid or mineralocorticoids.
When is “day 1” of a woman’s menstrual cycle?
The first day she notices menstrual bleeding
Which menstrual phase dictates the length of the cycle? How long is it usually?
How does this change at menarche, reproductive age, perimenopausal, & menopausal ages?
Follicular phase, normally 10-14 days
Menarche: immature hypothalamus → irregular follicular development rates and irregular cycles
Reproductive age: predictable follicular development, predictable cycles
Perimenopausal: older eggs, longer follicular development, longer cycles
Menopausal: no eggs, no cycles
How do contraceptives affect a woman’s reproductive abilities after she stops using them?
They don’t affect this once they are stopped
Millions primordial follicles are developed in utero. They grow and undergo atresia regularly unless rescued by _____
FSH
however while using OCPs, they are not “saved” and will just become apoptotic & die
______ stimulates growth of granulosa & initiates steroid production.
FSH
The appearance of LH receptors on the theca cells is directed by _____
FSH
Blood vessels also appear in the ovary, as this vasculature is necessary to deliver _____-containing cholesterol which is the basis of steroid hormone
VLDL
What is an “Antral Follicle”
Mature or Graafian follicle
PCOS - pathophysiology?
- Androgens are produced in excess by the ovary
- High levels of androgens overwhelm the aromatase enzyme
• Instead of conversion to estrogen, androgens are converted to more potent androgens
– Cannot become estrogen
– Inhibit aromatase
– Inhibit LH receptor formation
High local androgen environment == multiple small follicles are present but unable to fully develop.
Thus: No ovulation
- Infertility, irregular menses
- Hirsuitism, acne
The negative feedback of __a__ on __b__ normally controls oocyte production to just one per cycle.
a) estrogen
b) FSH
When follicle has more __a__ than __b__, it is “selected” as the dominant follicle
a) estrogen
b) androgen
What happens during the early vs. late halves of the Follicular phase?
Early:
- FSH stimulates ↑Estrogen production & ↑LH receptors
- Dominant follicle established (day 5-7)
- Estrogen levels increase, causing ↓FSH, ↑LH, & ↑FSH receptors on local granulosa cells so they respond to the little FSH that remains
Late:
- LH → ↑Androgen production by theca cells
- Remaining FSH → Conversion of androgen to Estrogen in granulosa cells, maintaining estrogen-dominated environment
What is the meaning of “luteinized” & to what cells does this occur/apply?
What is the outcome/effect of this?
It refers to the appearance & function of granulosa cells once they begin to secrete Progesterone in response to stimulation by LH.
The remaining FSH and LH plus the newly produced progesterone stimulate the release of enzymes which digest through the follicular cells allowing release of the oocyte with a little cluster (“cumulus”) of attached granulosa cells. This is referred to as Ovulation.
The LH surge stimulates meiosis from what phase to what?
prophase I → metaphase II
What hormone does the corpus luteum produce?
Progesterone
How does the Progesterone-only pill work to produce contraception?
By inhibiting the LH surge & ovulation
What does the addition of estrogen provide along w/ the effects of progesterone in contraception?
The addition of estrogen stabilizes the endometrium (so less irregular bleeding) & increases efficacy by also preventing FSH which is necessary for full follicular development.
Even after the dominant follicle is established, exogenous Estrogen will decrease FSH below sustaining level and the follicles life cannot be maintained.
How does Plan B work & what is it made of?
Currently Plan B is comprised only of progesterone which inhibits ovulation, and if ovulation has already occurred, also alters tubal transport of sperm to egg.
Where are Estrogen & Progesterone produced during the Luteal Phase?
Corpus Luteum
Inhibin is a protein hormone that inhibits __a__. Where is it made (b)?
a) FSH
b) granulosa cells (& corpora lutea)
Endometrial anatomy:
Lower 1/3 = _____ layer
Function & blood supply?
Upper 2/3 = _____ layer
Function & blood supply?
Lower 1/3 = basalis layer
– Regenerates functionalis layer
– Branches off uterine artery enter as basal artery
Upper 2/3 = functionalis layer
– Spiral arteries (branches off basal artery)
– Responsive to hormonal changes
During the Secretory phase, “Decidualization” refers to the appearance of the ___a___ under the effect of ___b___.
a) endometrium
b) progesterone
Luteal Phase Defect - Tx?
Exogenous Progesterone
basically the cause is that the women doesn’t have enough progesterone for the egg to properly implant
Patients undergoing IVF must be given progesterone when?
A. At the start of the cycle, to trigger follicular development
B. Mid-cycle to trigger ovulation
C. After ovulation, to promote a proper uterine lining
D. None of the above
D. None of the above
(A is incorrect because follicular development occurs in response to estrogen, stimulated by FSH.
B ovulation is triggered by the LH surge.
C While in a normally cycling woman, ovulation (specifically LH) triggers production of progesterone to promote a proper lining, IVF patients do not ovulate. Their developing follicles are harvested transvaginally and the oocytes fertilized in vitro.)
Withdrawal of _____ triggers endometrial shedding, or menses.
Estrogen & Progesterone
Is the chromosome number halved during meiosis 1, meiosis 2, or both?
Meiosis 1 only
A 20 yo woman whose first cousin had a baby with Down Syndrome asks you if she is at “high risk”?
A. Yes, a family history of DS increases her personal risk
B. No, her young age overrides any risk contribution of the family history
B. No, her young age overrides any risk contribution of the family history
20 years later, she wants to know what her options are to test for DS?
A. When the baby is born, the pediatrician will examine it for the distinct features of DS
B. She can have a karyotype made from a fetal skin cell in the second trimester of pregnancy
C. She can have fetal RNA in her blood analyzed for the amount of chromosome 21 in the first trimester of pregnancy
D. She can have a cell removed from her blastocyst at day 5 for karyotyping
E. All of the above
E. All of the above
When do sperm gain “Hyperactive motility”?
Once in the Fallopian tube
Because the egg can only survive in the tube for so long, most pregnancies result when coitus is within ______ of ovulation
3 days
What is sperm “capacitation”?
Combo of the sperm acrosomal enzymes breaking down the zone + sperm gaining hypermotility @ this point
Once fertilized, what does the egg do so that no other sperm can enter?
Zona glycoproteins cross-link
After fertilization, a __(#)__-cell morula enters the uterus.
8-cell morula enters the uterus
Risk factors for Ectopic Pregnancy?
- PID
- Previous ectopic
- Previous tubal surgery
- h/o infertility
- IUD in place
When does the embryo become a “Blastocyst” & what is it termed before this?
Blastocyst is just before implantation & is comprised of ~ 30-200 cells.
Before this, it is a “Morula”
2 circumstances under which a blastocyst will not implant?
- If it arrives @ an improperly prepared Endometrium.
- If it has an abnormal array of chromosomes.
(failure to implant → miscarriage)
Placenta formed by _____ after ovulation.
amount of time
2 weeks
- Blastocyst lines up with endometrium
- Adheres to endometrium
- ________ cells invade endometrium
Trophoblast cells invade endometrium
– Divide into cytotrophoblast & syncytiotrophoblast
– Produce β-HCG
ß-hcg can be given as an injection to infertility patients to do what function?
Mimic LH and trigger ovulation
Early function of β-hCG upon implantation?
Maintains corpus beyond otherwise limited lifespan.
If the trophoblast do not produce enough β-hCG then the luteum might still be lost. This is yet another reason for miscarriage.
Continued production of E+P is important so the endometrial lining does not inappropriately cleave off (taking the pregnancy with it).
IVF patients must be given external ______ to maintain pregnancy until ~ week 10-12.
Why?
progesterone
IVF patients have no Corpus Luteum b/c the oocytes were extracted from the follicle which then involutes. The CL is what normally would produce E & P to maintain pregnancy.
The _______ must continue production of Estradiol & Progesterone until how long after fertilization?
Corpus Luteum
Until week 7
then placental production of progesterone takes over…
Following fertilization, β-hCG doubles every __a__ during the first __b__.
(both are amounts of time)
a) 48 hours
b) 30 days
When is Peak Concentration of β-hCG reached?
~ 8 to 10 weeks gestation
What is the β-hCG “Threshold”?
Minimal level at which gestational sac can be seen on Ultrasound
~ 1500
Without any additional lab data or imaging, a patient with what 3-4 findings on exam can be assumed to have an ectopic pregnancy by clinical diagnosis alone?
Positive pregnancy test, bleeding, abdominal pain, & peritoneal signs
What are considered “peritoneal signs” in the clinical symptoms of Ectopic Pregnancy?
Peritoneal signs include rebound tenderness and guarding and indicate there is peritioneal irritation.
In the case of ectopic pregnancy, this may indicate there is blood in the abdomen, irritating the peritoneum.
What are 2 of a miscarriage seen on physical exam if a woman presents w/ blood spotting in the 1st trimester?
– Uterus may be enlarged
– Cervix may be open
A woman comes to the clinic in the 1st trimester of pregnancy w/ blood spotting. If no intra-uterine pregnancy is seen on ultrasound, what would her β-hCG have to be in order to diagnose Ectopic Pregnancy?
Above ‘Threshold’, i.e. >1500
- otherwise, follow & monitor β-hCG in 48 hours
- if it doubles = pregnancy!
- if it stays same or decreases, it’s either Ectopic or Miscarriage & the options for Dx/Tx are:
– Follow BHCG levels
– D+C
– Methotrexate
