Weeks 2 and 3 Development Flashcards
On day 8 the trophoblast differentiates into what?
Cytotrophoblast and the syncytiotrophoblast
On day 8 the embryoblast differentiates into what?
Hypoblast and epiblast
On day eight what cavity forms?
The amniotic cavity
What are amnioblasts?
These are epiblast cells taht are adjacent to cytotrophoblasts
What is the exocoelomic cavity?
The primitive yolk sac
On day nine what fills in the tiny endometrial wall?
Fibrin coagulum
On days 11 and 12 what is the trophoblast characterized by?
Lacunar spaces in the syncytium
When is the uteroplacental circulation established?
Days 11 and 12
When do extramebryonic mesoderm cells appear between the inner surface of cytotrophoblast and the outer surface of the exocoelmic cavity?
Days 11 and 12
When does the extraembryonic cavity (aka chorionic cavity) form?
Days 11 and 12
What are the 5 main things that happen in week two of development? (the week of two’s)
1.implantation complete; 2.trophoblast differentiates into 2 layers; 3.embryoblast forms 2 layers; 4.extraembryonic mesoderm splits into 2 layers; 5.2 cavities form
What are the five main things that happen in week three of development?
1.formation of primitive streak & node; 2.gastrulation occurs; 3.formation of notochord; 4.establishment of body axes; 5.growth of the embryo
What is gastrulation?
Formative process by which the three primary germ layers form (ectoderm, mesoderm, endoderm).
