early development Flashcards
Space between the two layers of lateral plate mesoderm is the primitive body cavity, which gives rise to…
Peritoneal cavity, pleural cavities, pericardial cavity
What does intermediate mesoderm give rise to?
urogenital system
before gastrulation, the embryonic disc is bilayered, afterwards it is
trilayered
at what week does the notochord happen?
week three
what is the notochord
axial mesoderm that forms a long cord along cranial caudal axis
What layer gives rise to all 3 germ layers?
the epiblast layer (light blue remember hypoblast was yellow)
Describe gastrulation in terms of what happens to epiblast cells
epiblast cells proliferate, lose their adhesion, and migrate to median plane of disc. Gastrulation starts when they migrate towards and thru the primitive streak.
by what week should the primitive streak be gone?
week four
Rule of two’s for week two?
embryoblast splits into TWO layers
Trophoblast gives rise to TWO tissues (cyto and syncytiotrophoblast
TWO eggo sacs form
TWO new cavities form (amnionic and chorionic)
Extraembryonic mesoderm splits into two layers(somatic and splanchnic
where does placenta come from?
both maternal and fetal tissues. The fetus contributes the chorion, and the mother provides the decidua
when is implantation?
approximately day 6
what is the endometrium called after implantaion?
the decidua
What hormone does the syncytiotrophoblast produce?
human chorionic gonadotropin, which provides feedback tothe ovary and corpus luteum which maintains the pregnancy
what goes on days 7-9 of human implantation?
Trophoblastic plate formation and invasion of uterine stroma by blastocyst
