Blastocyst implantation & gastrulation

Ccps 330

What does IPS1 and IPS2 do?

ISP1: a protase that is produced by blastocyst and perforates the zona pellucida

* main role is to help the blastocyst implant itself into the uterine endometrium

IPS2: secreted by uterine endometrial gland. It digest the zona pellucida surrounding the blastocyst

What is left after ovulation if no successful fertilization occurs

Corpus luteum

What are pinopodes?

• at surfdaçe of endometrium

• Swell

• Drinking feet

• Receptive phase

true or false: the uterine endometrial glands produces LIF. Once the blastocyst attaches to the uterine endometrium, the blastocyst produces LIF

True

What he inner and outer layer of the cytotrophoblast

• inner layer: rapid mitosis, source of syncytiltrophoblast

• Uter layer: syncitiotrophoblast , expand via fusion adjacent to cytotrophoblast cell

What are the two inner cell mass split?

Epiblast and hypoblast

What happens around 9 days?

• Proliferation of hypoblast cells moves towards blastocyst cavity

• Forms primary yolk sac

• Many cavities, lacunae (not on day 8 )in syncytiotrophoblast

Day 10

• Extraembryonic reticulum forms between cytotrophoblast and yolk

What havens to disc during gastrulation?

• transform from bilaminar disc into trilaminar disc embryo

• Trilaminar disc: ectoderm, mesoderm, endoderm

• Bilaminar: hypoblast epiblast

What is meant by endoderm cell ingression?

• endoderm cells goes from being static to migratory

• Mesoderm ingresses in day 16

Where does Embryonic folding occur

Folding of trilaminàl disc

What role does progesterone (Secreted by corpus luteum) play in the implanting of the blastocyst into the uterine endometrium?

“Deactivates” Mucin 1 (MUC-1) from uterine surface so that the L-selection found on blastocyst can bind to the binding site for L-selection on the uterine surface.

What is the HB-EGF receptor?

ErbB

Name these parts and what day does it happen.

Trophoblast. Occurs on day 7

What forms on day 8 and how?

The amniotic cavity forms on day 8 from the fluid between the epiblast cells

What is the bilaminar disc composed of and when does it form?

Bilaminar disc = embryonic epiblas + hypoblast

What does the amniotic cavity splits into in day 9

Amniotic ectoderm and embryonic epiblast.

What does gastrulation do?

Transforming the bilaminar disc into trilaminar disc

True or false: Inner Cell Mass of mammalian blastocyst is multipotent?

False they are pluripotent.