Flashcards in Embryology Deck (21):
Define a zygote
Single fertilised egg
When is the term embryo used?
Fertilisation to week 8
When is the term foetus used?
Week 9 until birth
State the 6 stages of embryogenesis
Gametogenesis - fertilisation - cleavage - gastrulation - formation of body plan - organogenesis
What is gametogenesis?
Germ cell formation
Where does fertilisation take place?
What is cleavage?
Rapid cell division to form a morula (mass of cells undestingushable from each other
At what point can the embryo begin to differentiate?
When it has formed a blastocysts
What is gastrulation?
The formation of germ layers in week 3
What are the three germ layers?
Ectoderm, endoderm and mesoderm
What is organogenesis?
Formation of organs and systems which will continue through foetal development
What does the trophoblast become?
Structural component, drives implantation
What does the embryoblast become?
What hatches from the zonal pellucid?
What does the ectoderm become?
skin and nervous system
What does the mesoderm become?
Axial skeleton, urogenital system and lining of body wall
What does the endoderm become?
Lining of gut tube and respiratory tract
4 Types of Congenital Heart Defects
Atrial Septal Defects
Ventricular Septal Defects
Outflow Tract Defects
Which type of ASD doesn't result in a mix of blood and why?
Patent foramen ovale - due to high pressure in the left ventricle
Tetralogy of Fallot - 4 factors?
Hypertrophy of the right ventricle
Overriding arch of the aorta
Ventricular septal defects