Embryology of the CVS

Question 1

Describe the formation of heart tube and name its constituent parts.

Answer 1

Fused heart tube starts to bulge and differentiate into arterial (cranial) and venous (caudal) ends.
5 regions formed:
- Truncus arteriosus
- Bulbus cordis
- Primitive ventricles
- Primitive atrium
- Sinus venosus

Question 2

What will the truncus arteriosus give rise to?

Answer 2

the aortic sac, from which the aortic arches will form

Question 3

Describe the formation of the bulboventricular loop

Answer 3

Primitive heart tube invaginates pericardium.

Growing tube becomes too large for pericardium and so needs to fold/loop —> bulboventricular loop

Question 4

Explain dextrocardia

Answer 4

Heart tube loops to left side (instead of right side), so ventricles come to lie facing the right (= dextro)