Bilaminar Germ Flashcards
Capacitation
sperm “condition” uterine tube as cap is exposed.
Acrosome reaction
sperm’s rectors exposed as glycoprotein cap is removed and then can bind to Zona Pellucida
Cortical Rxn
after sperm and oocyte membranes have fused, enzymes from lysosome released from granules around oocyte so only 1 sperm penetrates
zona rxn
hardening of zona pellucida so no more sperm can penetrate
Blastomere to blastocyst?
when zygote divides it becomes blastomere until 4 days when loses its potency and zona pellucida and becomes blastocyst at 32
inner vs. outer cells of 8-celled blastomere
inner: become embryo, yolk sac, and amnion
outer: form trophoblast
When/how does implantation occur
Day 16. Lining of uterus thickened by Progesterone secreted by Corpus Luteum allowing for trophoblasts to invade
Inner Layer of Trophoblast
cytotrophoblast, mononucleated
Outer layer of trophoblast
synchtotrophoblast:
releases Chorionic Gonadotrophin which is detected for pregnancy and keeps corpus luteum continuing
forms lacunae of blood in mom’s endometrium
amnioblast cells
come from inner blastomere cells. make up amnion
epiblast
top embryonic layer formed from inner blastomere cells. will make all dermal layers
hypoblast
lower embryonic layer formed from inner blastomere cells
contributes to 2nd yolk sac
blastocyst
below hypoblast will become yolk sac
different sack layers from inner to outer
amniotic sac 2nd. yolk sack chorionic cavity/Chorionic extraembryonic plate -->inner: somatopleuric -->outer: splanchnopleuric