Embryology Process: Flashcards
In Fertilisation what does the sperm bind with?
-Zona Pellucida Glycoprotein (ZP3)
What does the sperm release into the Zone Pellucida Glycoprotein it fuses with>
-Acrosal-digetsive enzymes
What happens after the egg and sperm fuse?
-Sperm releases its contents into egg
What X2 things does the sperm entry trigger?
- Completion of Meiosis 2
- Release of Oocyte granules
During meiosis II, the sister chromatids within the two daughter cells separate, forming four new haploid gametes.
What is an Oocyte?
Immature egg cell (Germline cell)
What does Totipotent, Multipotent and Pluripotent mean?
Totipotent- Can differentiate into ALL Types of cells
Pluripotent-Can specialise into ALL cell types except embryonic and placental cells
Multipotent- Cann only specialise into cells of the tissue found in
What is Compaction of the Morula and what does it form?
- Cells become tightly packed to increase surface area
- Forms- Blastocyst
What is a Morula formed from?
-Blastomere
What is Blastocyst Hatching?
Blastocysts bursts out of the Zona Pellucida Layer
-Interacts with endometrial lining of uterus for implantation
What happens when there is an accumulation of fluid in the Blastocyst?
-Signals production of ‘Cysts’-sacs with fluid
What is a Trophoblast?
-Outer cell layer of. Blastocyst
What is the Bilaminar Embryo?
-Embryo attached to tissue
How is the Bilaminar Embryo formed?
- Implantation
- Trophoblast attaches to endometrial tissue
How are the two layers formed in a Bilaminar Embryo?
Inner cell mass of embryo divides into two layers to form a Bilaminar Embryonic disc
Name the two layers formed in the Bilaminar Embryo.
- Hypoblast (front)
- Epiblast (back)
What hormone does the Trophoblast release that is used in Pregnancy Tests?
-Human Chorionic Gonadotropin: (hCG)
What is the Graafian follicle and Corpus Luteum?
- Graafian Follicle-Matures to release follicle, secretes oestrogen
- Corpus Luteum-Formed after ovulation, secretes progesterone in response to thicken
What is the ‘Extraembryonic Mesoderm’ ?
- Thick Layer formed in the Bilaminar Embryo
- Degenerates to form ‘Chronic Cavity’
What is combined to form the Umbilical Cord?
-Chronic Cavity + Connecting Stalk
How is the Trilaminar Embryo formed and what are its three layers?
- Gastrulation-Migration of epiblast cells through Primitive Streak
- Ectoderm, Mesoderm and Endoderm
What are the three parts of the Primitive Streak?
-X3 Parts;
Primitive Pit
Primitive Node
Primitive Groove
Put in order: Blastocyst Embryo Zygote Blastomere
1) Zygote
2) Embryo
3) Blastomere (forms morula)
4) Blastocyst (formed by compaction of Morula)
