Development of the arteries

Question 1

What structures are present in the earliest stage of great vessel development

Answer 1

Heart gives off 1st aortic arch artery which leads to dorsal aortae then to the single dorsal aorta

Question 2

What occurs in the seconds stage to occur in development of the great vessels

Answer 2

2nd aortic arch develops which also leads to dorsal aortae. Intersegmental arteries then develop from both left and right dorsal aorta, they supply surrounding tissue.

Question 3

What occurs after the development of the 2nd aortic arch.

Answer 3

3rd and 4th aortic arches develop while the 1st and 2nd arches degenerate. Meanwhile a longitudinal anastomotic vessels appears between the first 7 intersegmental arteries and grows crainally.

Question 4

What occurs after the development of the 3rd and 4th aortic arches

Answer 4

The dorsal aorta between the 3rd and 4th start to degenerate and the 3rd loses its connection to dorsal aorta while the 4th is still connected. 6th arch develops, close to developing lung buds. 7th intersegmental artery starts to grow outward to later supply the limb bud.

Question 5

What occurs after the 6th aortic arch develops?

Answer 5

4th and 6th arch is still patent between the aortic sac and the dorsal aorta. 6th arch sends a branch to lung buds which eventually forms pulmonary arteries. 1-6 intersegmental arteries degenerate while the bridge-like anastomotic artery becomes the vertebral artery. Right dorsal aorta starts to degenerate. Conus cordis and truncus arteriosus start to partition.

Question 6

What does the 3rd aortic arch form?

Answer 6

The common and internal carotid arteries

Question 7

What do the vertebral arteries join to form?

Answer 7

Basilar artery

Question 8

What does the 6th aortic arch retain its connection with?

Answer 8

Left dorsal aorta via the ductus anteriosus on the left only.

Question 9

The sinus venosum forms what?

Answer 9

Right atrium, SVC, Coronary sinus

Question 10

What does primordial atrium form?

Answer 10

Right and left auricles

Question 11

What do the embryonic pulmonary veins form?

Answer 11

Left atrium

Question 12

What does the primordial ventricle form?

Answer 12

Left ventricle

Question 13

What does the aortic sac form?

Answer 13

Proximal aortic arch and brachiocephalic trunk

Question 14

What does the 4th aortic arch form?

Answer 14

Right proximal subclavian artery and middle aortic arch on the left.

Question 15

What does the 6th aortic arch form?

Answer 15

Right pulmonary artery and left pulmonary artery and ductus anteriosus.

Question 16

What does the 7th intersegmental artery form?

Answer 16

Right distal subclavian artery and left subclavian artery

Question 17

What does the dorsal aorta form?

Answer 17

Right distal subclavian a, and descending aorta

Question 18

What is the cause of atrial septal defect (ASD)

Answer 18

Failure of proper development of septum secundum or failure of closure of foramen primum

Question 19

What is the ventricular septal defect caused by? (VSD)

Answer 19

Caused by a defect in the membranous or muscular portion of the IV septum, or the failure of fusion of membranous or muscular potions.

Question 20

What is the most common congenital heart defect?

Answer 20

Ventricular septal defect

Question 21

What is the patent ductus arteriorsus caused by?

Answer 21

No clear cause but may be due to chromosomal abnormalities, prematurity, low birth weight and hypoxia

Question 22

What is the cause tetralogy of Fallot?

Answer 22

It is caused by unequal division of conus cordis with an a malalignment of the aorticopulmonary septum

Question 23

What is the cause of the transposition of the great vessels?

Answer 23

Failure of the aorticopulmonary septum to spiral

Question 24

What is the cause of coarctation of aorta (narrowing of the aorta)

Answer 24

No clear cause but contraction of ductus anteriosus