Embryology of the heart and vessels

Question 1

What germ layer is the heart derived from?

Answer 1

Visceral Mesoderm

Question 2

What does lateral and craino-caudal folding do?

Answer 2

allow the heart to reach its final position in the thorax

Question 3

What are the 5 heart tube regions?

Answer 3

Truncus arteriosus
Bulbus cordis
Ventricle
Atrium
Sinus Venosus

Question 4

What does the Truncus arteriosus become once adult?

Answer 4

Aorta and pulmonary trunk

Question 5

What does the bulbus cordis become once adult?

Answer 5

Trabeculated part of Right ventricle

Outflow part of both ventricles

Question 6

What does the Ventricle become once adult?

Answer 6

Trabeculated part of Left ventricle

Question 7

What does the atrium become once adult?

Answer 7

Trabeculated part of both atria

Question 8

What does the sinus venous become once adult

Answer 8

Smooth part of right atrium

Coronary sinus

Question 9

What occurs during looping and folding?

Answer 9

Atrium goes dorsal and cranial
Ventricle is displaced left
Bulbus cordis goes inferiorly, ventrally to the right

Question 10

When does looping and folding occur?

Answer 10

Day 23

Question 11

Describe the 6 pairs of the aortic arch

Answer 11

1 and 2 → mostly obliterated (Maxillary a. and Stapedial a.)
(5 → rudimentary or absent)
3 → common carotid aa; first part of ICA
4 → right subclavian a.; part of aortic arch
6 → sprout branches that form pulmonary aa; ductus arteriosus on left

Question 12

What are the 3 venous systems that are found in the embryo?

Answer 12

Vitelline veins: drain Yolk Sac

Umbilical veins: Oxygenated blood from Placenta
Right degenerates; Left remains as Definitive Umbilical vein

Cardinal veins: give systemic venous system

Question 13

What are the systemic veins found in the embryo?

Answer 13

Anterior Cardinal Veins – drain head & neck

Posterior Cardinal Veins – drain trunk