Lecture 8: Implantation Flashcards Preview

COB Embryology > Lecture 8: Implantation > Flashcards

Flashcards in Lecture 8: Implantation Deck (11):
1

How long after fertilization does implantation begin?

Day 6

2

Blastocyst hatching

A small region of the zona pellucida overlaying the ICM dissolves and the blastocyst emerges, "shedding" the ZP in preparation for implantation

3

Functions of the zona pellucida

Promotes oocyte/follicle maturation, initiates acrosomal reaction, prevents polyspermy, acts as early immunological barrier between mother/embryo, facilitates trophoblast differentiation, prevents premature implantation

4

List the 4 stages of Implantation

1. Attachment of blastocyst to endometrium
2. Penetration of uterine epithelium
3. Invasion into tissues underlying epithelium
4. Erosion of maternal vascular supply

5

Which of the following is a function of the zona pellucida?

A. Nutritional supply for the egg
B. Initiates acrosomal reaction
C. Both of the above
D. Neither of the above

B. Initiates acrosomal reaction

6

What type of molecules facilitate attachment of blastocyst to endometrial epithelium?

Adhesion molecules such as integrins

7

What significant event occurs during the penetration of uterine epithelium?

Trophoblast separates into cytotrophoblast and synctiotrophoblast

8

Trophoblastic lacunae

Hollow cavities within syncytiotrophoblast which fill with maternal blood as endometrial blood vessels erode

9

Decidual reaction

Response of endometrial stroma cells to invading blastocyst; necessary because otherwise the trophoblast could potentially erode all the way through the endometrial wall

10

What is the result of the decidual reaction?

A massive cellular matrix that completely surrounds the embryo and fills most of the endometrium, IL-2 secreted to protect embryo from rejection

11

Ectopic pregnancy

Occurs when embryo is implanted somewhere other than the uterine wall