Branchial Arches

Question 1

Fate of the 1st branchial arch?

Answer 1

Regresses

Question 2

Fate of the 2nd branchial arch?

Answer 2

Regresses

Question 3

Which branchial arch(es) form the external carotid arteries?

Answer 3

horns of the aortic sac left behind by the regression of the first two arches

Question 4

Fate of the 3rd branchial arch? Other name for it?

Answer 4

Carotid arch

Common carotid and proximal internal carotid arteries

Question 5

Fate of the 4th branchial arches? Other name for it?

Answer 5

Systemic arch

Right: right subclavian
Left: arch of aorta

Question 6

Fate of the 5th branchial arches? Other name for it?

Answer 6

Fifth arch - regresses

Question 7

Fate of the 6th branchial arches?

Answer 7

Right: proximal right pulmonary artery

Left: left pulmonary artery AND ductus arteriosus

Question 8

What is the function of the ductus arteriosus and what does it become?

Answer 8

Connects the pulmonary trunk to the descending aorta, creating shunt from right ventricle to descending aorta

Ductus arteriosus —> ligamentum arteriosum

Question 9

Stuck?

Answer 9

See diagram in notability