Placenta Flashcards
When can sperm move through the cervix
When oestrogen levels are high just before ovulation
What activates meiosis 2
Sperm entry and Ca2+ spikes
What are the two differentiatied cell populations in the early embryo
Inner cells mass and trophectoderm
What is nidation
When the embryo implants int he decidua
What stage are the uterine glands torturus
Secretory/ early luteal
What is basal vacolutaion
When the stromal cells have vesicles in them of glandular secretions occurs in pre secretory phase
When does the villous period of the placenta begin
12 days post conception (3-4 weeks)
Once villous stage is reached what is occuring
Trophectoderm form cytotrophoblast which extends into intervillous spaces (ex lacunae) surrounded by syncytiotrophoblast. Primary villi formation
When do secondary villi form
When extraembryonic mesenchyme begins to infiltrate the primary villous
When do primary villi form
18-20 days post conception when fetal capillaries form in secondary villi
Describe the two forms of villi
Floating- mostly these are for transfer. Anchoring villi (cytotrophoblasts break through syncitiotrophoblast and invade amternal tissue.
What form the definitive placenta
Chorion frondosum
What forms chorinic membrane
Chorion levae
Incidence of pre-eclampsia
3-8%
What is the increased risk for mother if PE before 34 weeks
CVD
