Lect. 8 - Implantation Flashcards Preview

Embryo - Exam I > Lect. 8 - Implantation > Flashcards

Flashcards in Lect. 8 - Implantation Deck (22):
1

How soon after ovulation does fertilization typically occur?

12 hours. (in upper ampulla)

2

Uterine tube transport - End of day 1

2-cell stage in isthmus

3

uterine tube transport - day 3

morula in isthmus/corona radiata lost by this time

4

uterine tube transport - day 4

blastocyst in uterus

5

uterine tube transport - day 5

loss of ZP

6

uterine tube transport - day 6

beginning of implantation

7

Blastocyst hatching

A small region of the ZP, usually directly over the ICM in the primate, dissolves and the blastocyst emerges from the hole.

8

major functions of the ZP

promotes maturation of the oocyte and follicle;
barrier; initiates the acrosomal reaction; prevents any additional sperm from reaching the zygote; porous filter through which certain substances secreted by the uterine tube can reach the embryo; immunological barrier b/w the mother and the antigenically embryo; prevents the blastsulas of the early cleaving embryo from dissociating; differentiation of trophoblastic cells; prevents premature implantation of the cleaving embryo into the wall of the uterine tube.

9

Stages of implantation

1. attachment of expanded blastocyst to the endometrial epithelium
2. penetration of the uterine epithelium
3. invasion into the tissues underlying the epithelium
4. erosion of the maternal vascular supply

10

what facilitates attachment of the blastocyst to the endometrium?

adhesion molecules expressed by the endometrium and also by the trophoblast cells

11

cytotrophoblast

closest to ICM

12

syncytiotrophoblast

closest to endometrium; its projections penetrate the endometrial basal lamina and invade the stroma

13

decidual reaction

response of the endometrial stroma cells to the invading blastocyst

14

what would happen w/o the decidual reaction?

possible the trophoblast would erode through the endometrial wall

15

what are decidual cells derived from?

endometrial stroma cells that accumulate glycogen and lipid droplets

16

result of the decidual reaction

massive cellular matrix that completely surrounds the embryo and fills most of the endometrium

17

IL-2 in the decidual reaction

prevents the mother's immune system from recognizing the embryo as a foreign body
**primary function

18

most common place for ectopic pregnancies to occur

uterine tube

19

w/i the uterine tube, where is the most common place for ectopic pregnancies

ampulla

20

if ectopic pregnancy happen outside of the reproductive system where's most common?

rectouterine pouch

21

where is low pH most important?

vagins

22

transcription of what is required to permit cleavage to proceed to the 2-cell stage in mammalian embryos

Oct 4