Cardio embryology

Question 1

When does the primordial heart start to function?

Answer 1

4th week

Question 2

What are the stages of blood vessels development?

Answer 2

Differentiation of mesenchymal cells
Angioblasts
Blood Islands
Small cavities appear in blood islands
Endothelial cavities fuse to form endothelial channels

Question 3

How do the heart tubes form?

Answer 3

Angioblastic cords canalise to for heart tubes
These merge, leaving one end with one exit, and one with two (like an upside down Y)
This joins bloodvessels forming primordial CVS

Question 4

What are the parts to the heart tube?

Answer 4

Truncus arteriosus – arterial end
 Bulbous cordis
 Ventricle
 Atrium
 Sinous venosus – venous end

Question 5

What happens to the truncus arteriosus?

Answer 5

Forms aortic sac
Which forms aortic arches
These terminate in the dorsal aorta

Question 6

What forms the pericardium?

Answer 6

Intra-embryonic coelom
Fibrous pericardium/parietal layer of serous pericardium formed from somatopleuric mesoderm
Visceral layer formed from splanchnopleuric mesoderm

Question 7

How does the cardiac loop form?

Answer 7

The bulbus cordis is brought downwards as the ventricle is squashed downwards
Causesatrium to be shifted on top
Due to bulbus cordis and ventricle growing faster than other areas

Question 8

What is dextrocardia?

Answer 8

Where heart tubes bend to the left instead of right

Can be associated with situs inversus