Lecture 1: Conception Flashcards
After the sperm enters the oocyte which area moves away from the oocyte to create a space and prevent more sperm entering?
The zona pellucida
After the sperm enters the oocyte the sperm head enlarged and becomes what?
The Male pronucleus
After the two pronuclei have fused, what is the whole entity called?
A zygote
What is the morula?
Solid ball of ~16 cells on day 4.
What is the whole entity called when it starts filling with fluid?
A blastocyst
What is the purpose of compaction?
To maximise cell to cell contact.
After how many days does the blastocyst “hatch” from the zona pellucida?
5
Which is the outer part of the blastocyst trophoblast?
Syncytiotrophoblast
What are the two layers of the bilaminar disc?
Epiblast and Hypoblast
What part of the secondary oocyte do the sperm first attach to?
The corona radiata.
What is the thin end portion of the fallopian tube called?
Isthmus
What is the whole entity called from zygote to blastocyst stages (commonly wrongly known as egg)?
Conceptus
Once the morula has differentiated into the inner cell mass and the trophoblast, what does the trophoblast then differentiate into and then do?
Differentiates into epithelium and starts pumping in sodium from the maternal environment so that water follows by osmosis and creates the blastocyst cavity.
The Heuser’s membrane is formed by which cells?
The hypoblast cells
Between which two layers does the extraembryonic mesoderm form?
Between the Heuser’s membrane and the cytotrophoblast membrane.
