Reproduction Flashcards
Describe the early follicular phase.
Increased FSH and LH levels relative to baseline. Low estrogen and progesterone levels.
Describe the late follicular phase.
Follicles grow/mature. Estrogen levels increase (positive feedback) and FSH levels decrease (negative feedback).
Describe the process of gonadotropin secretion.
The hypothalamus releases GnRH which causes the anterior pituitary to release LH and FSH, which cause the ovaries to secrete estrogens and progesterone.
“The ____ is the primary source of estradiol in ______ women”
Ovary; pre-menopausal
Where is estradiol converted to estrone and estriol?
Liver
What are the major circulating estrogens in pre-menopausal women and men/post-menopausal women?
Estradiol and Estrone
What does aromatase do?
Converts testosterone to estradiol and androstenedione to estrone.
What does estradiol bind to in circulation?
Sex hormone-binding globulin (SHBG) and albumin (lower affinity)
What does estrogen increase the risk for?
Stroke and DVT in post-menopausal women.
Also, heart attack and gallbladder disease, as well as cervical and endometrial cancers.
What are some other effects of estrogen?
Increase HDL and decrease LDL. Decrease bone resorption and increase body fat, salt and fluid retention.
Estrogen therapy is contraindicated in which people?
Breast or endometrial cancer, endometriosis and undiagnosed vaginal bleeding.
Tamoxifen has pro-estrogen effects on where?
Uterine endometrium and bone. This is why tamoxifen increases the risk for endometrial cancer and arthritis.
How does Clomiphene Citrate work and what is it used for?
It blocks estrogen binding to receptors in the hypothalamus and inhibits negative feedback. This allows increased secretion of gonadotropins and LH, leading to increased ovulation.
Used for stimulating ovulation in patients with ovulation disorders who want to be pregnant.
Where is progesterone produced?
Females: corpus luteum and placenta.
Males: testes
Both: adrenal cortex
What are the physiologic effects of progesterone?
Stimulates the endometrium to develop secretory glands and support implntation.
Long-term use has atrophic effect on endometrium (used for endometrial cancer).
High levels trigger a negative feedback on the hypothalamus to stop releasing gonadotropin, suppressing ovulation.
What are the Estradiol esters?
Estradiol valerate and estradiol cypionate
What are the conjugated estrogens?
Estrone sulfate and equilin sulfate
What are the alkyl estrogens?
Ethinyl estradiol and mestranol
What are the two types of progesterone?
Micronized and transvaginal (minimal systemic side effects).
What are the synthetic progestins?
Medroxyprogesterone, Norethindrone, Norgestrel, Megestrol
Which has more side effects, natural or synthetic progesterones?
Synthetic (hirsutism and acne)
What is progesterone contraindicated in?
Thromboembolic disorders.
Do not give to patients with liver disease, pregnancy (atrophic effect on endometrium) and undiagnosed vaginal bleeding.
What is the birth control pill?
An estrogen-progestin combination.
Constant levels of estrogen suppresses FSH secretion, thus preventing follicle maturation, and suppresses the LH surge.
Progestin suppresses LH secretion and thickens the cervical mucus, making it impenetrable to sperm. It also eventually leads to endometrial atrophy.
What is the Mini Pill?
Progestin-only. Useful for lactating women (estrogen reduces milk production) and for patients with a history of endometrial cancer.
It’s more likely to produce irregular menstrual cycles (estrogen provides stability to the endometrium)
