Implantation

Question 1

Functions of Zona Pellucida

Answer 1

Surrounds developing embryo until it reaches the uterus

Question 2

Uterine tube transport timeline following fertlization

Answer 2

Fertlization usually in ampulla within 12 hours of ovulation

2 cell stage by end of day 1

Murola in isthmus with loss of corona radiata by day 3

Blastocyst in the uterus by day 4

Day 5: loss of zona pellucida

Day 6: implantation begins

Question 3

Stages of implantation

Answer 3

Attachment of blastocyst to the endometrial epithelium

Penetration of the uterine epithelium

Invasion into tissues under the epithelium

Erosion of the maternal vascular supply - for sustenence

Question 4

Trophoblast

Answer 4

Breaks into cytotrophoblast and syncytiotrophoblast

Syncytiotrophoblast - contact with endometrium - invades the endometrial stroma

Question 5

What is the decidual reaction

Answer 5

The response of the endometrrial stroma cells to the invading blastocyst, without the blastocyst might evade all the way through.

Accumulation of glycogen and lipid droplets ..?

Creates massive cellular matrix that completely surrounds the embryo - secretion of IL-2 keeps mothers immune system from attacking fetus: prupose - to provide the developing embyro an immunological safe site.

Question 6

What is the most common site of ectoptic pregnancy?

Answer 6

Ampulla! - most common

Followed by Isthmis.