Pregnancy and Childbirth Flashcards
0
Q
The tropoblast differentiates into:
A
1) tropoblast(outer)
2) cytotropoblast(inner)
1
Q
What secretes the protease that breaks down the zona pellucida?
A
The uterus, 6 days after fertilization
2
Q
What secretes the protease that breaks down the uterine endometrium for implantation?
A
The syncytiotropoblast
3
Q
What is the Decuiduoma Response?
A
When the uterine reacts to the invasion of the blastocyst by growing over the implantation site–>marks completion of implantation
4
Q
Amnion
A
- grows over forming embryo
- amniotic cavity becomes filled with amniotic fluid
- fluid protects fetus against mechanical shock and supplies water and other material to fetus
5
Q
Allantois
A
- helps form membranes for blood vessels of umbilical chord
- resivior for moving toxic waste
- mainly a vestigial structure
6
Q
Chorion
A
- derived from the cytotrophoblast and surrounds embryo 1 month after development
- forms important component of placenta
7
Q
Pregnancy with dizygotic twins
A
- 2 zygotes formed and 2 embryos implanted into uterus
- when implanted seperately: 2 placentas, chorions, and amnions apear
- when implanted together: single placenta, fused chorions, and 2 amnions present
8
Q
Pregnancy with monozygotic twins
A
-produces two embryos with single placenta and chorion, but 2 amniotic sacs`
