Introduction to embryology Flashcards
what is an oocyte
female germ cell
what blastomere
cleaved cells from fertilised ovum
in which trimester do most the organs develop
1
which trimester does rapid foetal growth occur
3
what occurs after zygote is formed
cleaved to blastomeres
what is a fully successive cleavage to a amss of blastomeres called
morula
On day 4 when the morula enters uterine cavity, what provides is nutrients
Uterine milk
what is the marula surrounded by
zona pellucida
at the 32 cell stage what happens to the morula
becomes a fluid filled cavity called the blastocyst cavity
what is a blastocyst
Developed blastotocyst cavity
briefly define what occurs on day 1
Cleavage of zygote to 2 blastomeres and 2 polar bodies
briefy define what occurs on day 2
cleavage of zygote to 4 cells
briefy define what occurs on day 3-4
morula
briefly define what occurs on day 5
blastocyst
During formation of blastocyst which 2 cells populations arise
Embryoblast and trophoblast
Define trophoblast
-outer superficial layer forming wall of blastocyst
Define embroblast
inner cell mass which develops into the embryo
What does the trophoblast develop into
Chorionic sac that surrounds
-foetus
-foetal portion of placenta
what is the site of early exchange between mother and child of nutrients and wastes
chorionic sac
On the 5th day what hatches from the zona pellucida
blatocyst
where does the blastocyst attach 2 days after hatching from zona pellucida
(endometrium) Posterior portion of fundus or body of uterus
Around 7th day were more firmly does the blastocyst attach
endometrium eventually burrowing into the endometrium and is surrounded by it
How does the blastocyst merge with and burrow into the endometrium
It secretes digestive enzymes that eat away the endometrial lining at the site of implantation.
