Post-implantation development Flashcards
Describe invasive implantation
trophectodermal cells breaking through endometrium and invading into the underlying stroma
- decidualization
differences between invasive and non-invasive implantation
invasive consists of decidualization
outline non-invasive implantation
blastocyst come into contact with endometrium - apposition
trophectoderm multiply and invading in the endometrial tissues - adhesion
trophoblasts grow into villi and and with blood vessels form the placenta
what maintains progesterone production
human chorionic gonadotrophin secreted by syntiotrophoblasts of embryo and placenta
name the two types of diapause
obligatory diapause and facultative diapause
what do polar TE give rise to
ectoplacental core and extraembryonic ectoderm
what do mural TE give rise to
trophoblast giant cells
function of trophoblast giant cells
invade uterine wall and modify maternal blood vessels preparing them to perfuse placenta
why do cytotrophoblast cells block spiral arteries
allow embryo to develop in low oxygen environment and reduce risk of free radicals
Name 5 functions of placenta
- connects fetus to mother
- transfer nutrients from maternal blood supply to fetus and waste products away
- keep two blood supplies separate
- immune system is down-regulated
- synthesize biologically active molecules
function of yolk sac
provide nutritional support
what forms the yolk sac
primitive endoderm and between visceral endoderm n parietal endoderm in mouse
what is different in fetal membranes in mouse n human
outermost layer in mouse is derived from parietal yolk sac (parietal endoderm) and human is chorion (mainly cytotrophoblast cells)
what is the function of fetal membranes
retain amniotic fluid around embryo, paracrine regulators of amnion, chorion and decidua
describe the human embryonic development
formation of bilayer disc (epiblast and hypoblast), axis formation, gastrulation and organogenesis
