Female Repro Physio (Day 2 - Fertility) Flashcards
What hormone has a negative feedback on FSH production and causes thickening of the endometrium?
Estrogen
Describe the mechanism by which Clomiphene is a treatment for infertility.
Clomiphene is an estrogen receptor-alpha antagonist that blocks the E2-dependent negative feedback effect, so that FSH secretion can go on unhindered. This helps develop many pre-ovulatory follicles in which one may eventually make a viable oocyte for fertilization.
What ovarian structure surprisingly still works despite the process of extracting and culturing the oocyte for in vitro fertilization (IVF)?
Corpus Luteum still functions to make Progesterone and estrogen despite oocyte retrieval being performed just before the day of ovulation.
What hormone is more potent than LH to its own receptor? What is its clinical significance?
Human Chorionic Gonadotropin (hCG) binds more strongly to LH receptor and is supplied as an exogenous gonadotropin to control follicular growth. This is an early marker for pregnancy.
Define primary amenorrhea. How does it differ from the secondary condition?
Primary amenorrhea is the status of a female that has never had a period. Secondary amenorrhea describes having had periods that abruptly stopped.
Name some signs and symptoms associated with higher than normal levels of testosterone in women.
Severe facial acne and a lot of body hair.
A risk of dyslipidemia that can lower HDL, thus being a cardiovascular risk factor.
List at least 3 signs associated with a loss of function in Estrogen-receptor-alpha?
Estrogen-resistant Syndrome is associated with…
- High FSH and E2 levels - no negative feedback
- Osteoporosis - lack of ER-alpha
- Short stature - growth plates prematurely close
What treatment can be provided to a woman with primary amenorrhea that results form a loss of ER-alpha?
Norethindrone = Progestin contraceptive would enable negative feedback to occur in order to disrupt the GnRH pulse generator. This lowers E2 and gonadotropins. It also reduces the size of ovarian cysts.
What is the significance of days 20-24 in the menstrual cycle, in regards to pregnancy?
This is the window for implantation within the luteal phase that is brought upon by high E2 and P4 levels.
What weeks are in the 3rd trimester of pregnancy?
Weeks 27-39 of gestation
What weeks are in the 2nd trimester?
Weeks 13-26 of gestation
What weeks are in the 1st trimester of gestation?
Weeks 1-12 of gestation after implantation.
During what part of gestation is delivery supposed to occur?
Weeks 39-42 of gestation
Describe the mechanism for maternal recognition of pregnancy.
At weeks 3-4 the neuroendocrine function in HPA shifts to the placenta. Placental GnRH stimulates trophoblast to secrete hCG which bings LH-R. This stimulates a potent LH activity at the corpus luteum to make A LOT of Progesterone which inhibits pituitary gonadotropins. This effectively stops the mother-to-be’s cycling pattern.
What are the respective roles of Cortisol and DHEAS in the fetus? What stimulates the fetal adrenal gland to secrete these things?
Cortisol is essential for the development and growth of the fetus. DHEAS is a substrate for placental steroidogenesis to make Estriol (E3). The maternal P4 stimulates the fetal adrenal gland to secrete these products.
Why does E3 supercede E2 in the 3rd trimester of gestation? What are these estrogens involved in at this time?
E3 is necessary for activation of uterine Estrogen receptor, when E3:E2 ratio increases to 10:1. They are involved in myometrial function and mammary gland development for lactation.
Describe the functions of Progesterone (P4) in the mother during gestation.
P4 is the mother of all pregnancy hormones, necessary for maintaining a quiescent myometrium. It also increases intravascular volume, elicits vasodilation to perfuse the placenta, increases RBCs and maternal HR.
During pregnancy, why is maternal central venous pressure and pulmonary artery pressure unchanged, despite the increased HR?
Cardiac output increases to match the increase in venous return and reduction in pulmonary vascular resistance, respectively.
How does a pregnant woman’s cardiac curve reflect in terms of cardiac output and total peripheral resistance compared to non-gravid?
Increased CO (from HR) and decreased TPR (from vasodilation)
Define the origin and effects of Relaxin.
Relaxin is a local vasodilator secreted from corpus luteum that, when combined with P4, vasodilates over Angiotensin II’s effect (that was stimulated by E2). This protein also softens the rib ligaments of the mother thus increasing the subcostal angle and decreasing FRC + ERV (restrictive pattern).
What effect does Progesterone and E2 have on AVP? What are the downstream effects?
P4 and E2 increase AVP secretion from posterior pituitary that was activated by magnocellular neurons in the hypothalamus. AVP indirectly increases Cortisol levels and distal water reabsorption. The vasoconstrictive effects are hampered by CL’s Relaxin and Placental P4.
How does pregnancy relate to glucosuria at the level of the kidney?
Pregnancy is associated with decreased vascular resistance and increased perfusion. This increases GFR which enables SGLT to saturate glucose resulting in glucosuria. It is also associated with low creatinine and BUN levels.
List some factors that decrease TPR from the 2nd trimester to the time just before delivery.
Relaxin, Estrogen, Progesterone, Nitric Oxide decrease TPR and diastolic pressure during this time of gestation.
List at least 5 factors that control arterial blood gases.
Cardiac output (Q), ventilation (V), diffusion, Hb content, pH, temperature, 2,3-BPG
