Systems development III: Cardiac embryology Flashcards
What percentage of all congenital defects are cardiac?
20%
Give a brief overview of the 7 main stages of cardiac development?
Folding brings heart tubes into ventral midline Heart tubes fuse (day 22) Heart tube begins to beat (32) Heart looping occurs Separation occurs Aortic and pulmonary trunks divide Valves develop
Where does the heart start to develop?
In the cardiogenic area inferior to the notochord
What do mesodermal and endothelial cells become?
Mesodermal- blood and vasculature
Endothelial- vessels at around week 3
Why does the heart tube fold?
To develop the 4 chambers of the heart
What do the ends of the heart tube divide to form at the anterior aspect?
The arterial trunks- then you have the ventricles followed by the atria. The venous channels or cardinal veins form at the inferior aspect
What does the heart do after the arterial trunks and venous channels are formed?
The heart tubes turn on the side to make a c shaped bending
What follows the c shaped bending?
S shaped bending to bring the atria and ventricles together
What does the gap between the atria and ventricles form?
AV groove
What is septation?
The process of the chambers being divided to form the atria and ventricles of the left and right sides of the heart
What is septation facilitated by?
Endocardial cushions which develop as outgrowths of mesodermal tissues in atrioventricular canal
What do the endocardial cushions eventually form?
The valves of the heart which separate the atria and ventricles
What little holes are there in the heart?
Septum primum grows downwards first and then the septum secondum. The foramen oval is formed from the gap between the AV body and the septum secondum
In the early embryo, what origin is all of the vasculature from?
Mesodermal
What are the first veins called?
Cardinal veins (with anterior/posterior and common branches