Fertilization Flashcards
At 20 weeks’ gestation, women have about ___________ oocytes. The half-life of these is about _________.
6-8 million; 10 years
Oocytes are suspended in __________ for about 45 years.
prophase I
The _____________ allows sperm to break through the zona pellucida.
acrosomal reaction
What are some problems with blastocyst sampling?
Blastocysts may be mosaic
Embryos undergo editing
What is a less invasive way to investigate embryos?
Most aneuploidies arise from the mother. Some labs have started analyzing the discarded polar bodies; if polar bodies have chromosomal abnormalities then it’s likely that the embryo does, too.
Give the WHO’s normal range for semen analysis.
- Volume greater than 1.5 mL
- Concentration greater than 15 x 10^6 / mL
- Motility greater than 32%
- Morphology at least 4% normal
When should hormone levels be measured in a woman to evaluate for infertility?
Just after menstruation, in the early follicular phase
FSH and E2 are the indicators.
What molecule helps keep chromatin condensed?
Protamine
Sperm binding to the zona pellucida is mediated by _____________.
ZP3
Fusion of the sperm membrane with the oocyte membrane causes the release of ______________.
hyaluronidase and acrosin
FSH used to be examined to determine the functional health of the ovaries and follicles, but __________ is a better indicator and is now used.
AMH
Describe the overall chemistry of the acrosome reaction.
Binding to the oocyte leads to activation of a Gq receptor that leads to sustained calcium entry.
______________ is responsible for sperm-oocyte fusion.
Fertilin
What cell counts occur in the first week after fertilization?
- One day: two cells
* Three days: four cells
