Embryology Flashcards
What is cleavage?
Several mitotic divisions leading to the formation of morula.
What is compaction?
Formation of blastocyst
What occurs during fertilisation?
Oocyte is released from the ovary, travels along the Fallopian tube and is fertilised by sperm in the ampulla. A fertilised oocyte is called a zygote.
What is the ideal site for implantation?
The posterior uterine wall.
Wha type of cells are there before and after compaction?
Before compaction the cells are totipotent so they can differentiate into any type of cell. After compaction they become pluripotent so they can differentiate into many types of cells.
What occurs during hatching?
On day 5, blastocyst hatches from Zona pellicuda and can now interact with uterine surface to implant
What emerges from outer cell mass?
Syncytiotrophoblast, cytotrophoblast
What does the inner cell mass become?
The bilaminar disk- epiblast and hypoblast
What is an ectopic pregnancy?
An implantation at a site other than the uterine body, most commonly in the Fallopian tube. It’s a life-threatening emergency.
What is placenta praevia?
When implantation occurs in the lower uterine segment, it can cause haemorrhage in pregnancy, so a c-section delivery is required.
What does epiblast differentiate to?
Differentiates to form the trilaminar disc, the layer are ectoderm, mesoderm and endoderm. All 3 layers derive from the epiblast.
What do notochord signals cause?
Causes the overlying ectoderm to thicken and curl towards each other, creating the neural tube.
