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23 Cards in this Set
- Front
- Back
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At what gestational week do PGC's appear in yolk sac and migrate to genital ride and PGC's undergo mitosis?
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WEEK 4!
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How much testosterone does the ovary produce?
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~25%
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At what gestational week do PGC's arrive at genital ridge and sex cord formation supports germ cells?
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WEEK 6!
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During what gestational weeks do ovarian differentiation / reproductive tract differentiation / meiosis and meiotic arrest occur?
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WEEKS 8 - 12! Remember that at week 7, things are STILL UNDIFFERENTIATED.
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What do sex cord cells become?
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Granulosa cells! Differentiated supoprt cells that support GERM CELLS...
Combine with germ cells to become FOLLICLES |
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What do you get when you combine sex cord cells with PGC's?
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Follicles!!! Sex cord cells become granulosa cells.
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How many oocytes remain at birth?
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Original number of ~5-7 million at birth undergoes ATRESIA to ~1 million at birth.
~80% loss!!! |
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TRUE/FALSE
Follicles are wholly dormant during pre-pubescence. |
FALSE!
Follices undero development, but lack of hormonal signaling results in follicular atresia. Gonadotropin levels are suppressed by age 1. |
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How many germ cells are present at puberty?
How many germ cells are ovulated? |
~300K - 500K at puberty.
~400-500 eggs are ovulated. |
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How much time does it take from primary follicle recruitment until ovulation?
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85 days!
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What is the concept of a dominant follicle?
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At antral follicular stage (beginning of hormonal dependence), there are ~20 eggs that can respond to FSH. However, only ONE follicle is dominant and will be selected.
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What are two "number" points where atresia rates increase?
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At 25,000 remaining follicles.
~10 - 15 years pre-menopause. At this point of increased atresia, hormonal levels are varying and MENSTRUAL CYCLE IRREGULARITY becomes more common. |
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What is the HALLMARK of PERIMENOPAUSE?
How long is perimenopause. Around what age? |
Menstrual Cycle IRREGULARITIES.
Approximately 5 years. Average age 46. |
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What is HALLMARK of menopause?
What is average age of menopause? What are FSH/LH/Estradiol levels of menopausal women. |
Point in time where menstruation ceases due to loss of ovarian activity.
Between 50 - 52 years. FSH / LH are high. Estrogen levels are low. Therefore there is NO INHIBITORY FEEDBACK OF ESTROGEN ON LH/FSH. |
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Which of the three affects age of menopause?
Smoking, OCP, Age of menarche? |
Smoking
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What is definition of Premature Ovarian Failure?
How do you biochemically diagnose this? |
Cessation of ovarian function by age 40.
Elevated FSH/LH levels on multiple occasions more than ONE MONTH APART. |
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What are some causes of premature ovarian failure?
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Congenital - Chromosomal (TURNERS SYNDROME)
Autoimmune - Polyglandular Autoimmune Infectious - mumps Chemo/radio |
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What is TURNERS SYNDROME?
Why is signficant to premature ovarian aging? |
TURNERS SYNDROME = females with only one X chromosome. Therefore, female DOESN'T MAKE SUFFICIENT HORMOME. Balance of atresia/follicular development is tilted to ATRESIA.
Symptoms include: Delayed puberty/early menopause... Short stature ... renal/cardio abnormalities. |
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What is a particularly bad chemo drug for premature ovarian aging?
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ALKYLATING AGENTS b/c they are not cell-cycle specific and so NON-PROLIFERATING cells can be damaged.
Primary target for alkylating agents is GRANULOSA CELL. |
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What is the LD50 of oocytes in radiation exposure?
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4 GRAY.
Radiation levels and subsequent ovarian damage ARE DOSE-DEPENDENT. More is bad. |
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What is the mechanism behind autoimmune premature ovarian failure?
How many types are there? |
CROSS-REACTIVITY with auto-antibodies directed at other tissues because ovarian autoantibodies are rarely positive.
Two types: TYPE 1: 60% risk of ovarian failure. TYPE 2: 10% risk of ovarian failure. |
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What is major risk and major benefit of Hormone Replacement for women with Premature ovarian failure?
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Benefits: Osteoporosis prevention. Hot flashes reduced.
Risk: DVT! |
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Which is more effective?
Oocyte cryopreservation or Embryo cryopreservation? |
EMBRYOS!
Oocyte cryopreservation is in trials. |
