Flashcards in Embryology Deck (49)
What is embryology?
The study of progression from a single cell to a baby in 9 months
What is special about zebra fish?
Translucent eggs that are outside the mother
Study birth defects
Where does fertilisation take place?
Ampullary region of the fallopian tube
How long is a sperm viable for?
How long is a secondary oocyte viable for?
Why aren't sperm rejected as they are foreign bodies?
Antibodies only form if the sperm gets in contact with the blood
Tight junctions stop sperm passing into blood
When is the germinal stage?
Fertilisation to the end of the second week
When is the embryonic period?
Beginning of third week till the end of the eighth week
When is the Foetal period?
Beginning of ninth week to birth (38 weeks)
What is the Zona Pellicuda?
Stops the blastocyte from adhering to oviduct
The loss of it is called hatching
What does trophoblast mean?
Food bud- becomes the yolk sac and placenta
What is Histiotrophic nutrition?
Nutrition provided to the embryo not from the maternal blood
Before week 12
What is haemoptrophic nutrition?
Nutrition provided by the mothers blood
After week 12
What is the implantation site?
Site of formation the placenta
Usually upper part of the body of the uterus in the posterior wall
What is an ectopic pregnany?
Fetus develops outside the Uterus
What is placenta previa?
Placenta blocks the neck of the uterus so interferes with delivery
What is Syncytium?
What is syncytiotrophoblast?
Cells that merge together in the trophoblast
What is Cytotrophoblast?
Cells in the trophoblast
What happens in the second week of development?
Trophoblast differentiates into 2 layers
Embryoblast forms 2 layers- epiblast and hypoblast
Hypoblast forms the yolk sac and chorionic cavity
What happens during the embryonic period?
All major systems and structures are formed
When is the greatest risk of major congenital malformations?
What are the key events and processes in early development?
Fertilisation and implantation
Where do new features appear in the third week?
Dorsal surface of the epiblast
What is an ectoderm?
Organs and structures that maintain contact with outside world
What is a mesoderm?
What is an endoderm?
What is Situs inversus?
Complete mirror image viscera
Commonly results from immotile cilia
No associated morbidity
Problem arise if normal and mirror image disposition
What are the clear right and left body differences?
Liver on the right
Stomach and spleen on the left
Left lung has 2 lobes
Right lung has 3 lobes