Great Vessel Embryology

Question 1

Aortic arches

Answer 1

• Connect aortic sac (distal TA) to right and left dorsal aortae
• Numbered 1-6 (no 5 in humans); 1 develops first

Question 2

1^stAortic Arches

Answer 2

Regress and form part of maxillary a.

Question 3

2^nd Aortic Arches

Answer 3

Regress and form part of stapedial a.

Question 4

3^rd Aortic Arches

Answer 4

Extend and remodel to become the L/R common, internal, and external carotid arteries

Question 5

4^th Aortic Arches

Answer 5

• Right 4^th aortic arch → proximal R subclavian a.
• Left 4^th aortic arch → arch of the aorta

Question 6

6^th Aortic Arches

Answer 6

• Right 6^th aortic arch → right pulmonary a.
• Left 6^th aortic arch → left pulmonary a. and ductus arteriosus

Question 7

7^th Segmental Artery

Answer 7

• Right 7^th segmental a. → distal R subclavian a.
• Left 7^th segmental a. → entire L subclavian a.

Question 8

Dorsal Aortae

Answer 8

• Right dorsal aorta → middle of the R. subclavian a. (the rest regresses)
• Left dorsal aorta → descending thoracic aorta

Question 9

Aortic sac

Answer 9

Forms the ascending aorta and brachiocephalic a.