the distal left sixth arch becomes the ductus arteriosus, the proximal sixth arches bilaterally contribute to the proximal branch pulmonary arteries

The sixth right arch disappears; the sixth left arch gives off the pulmonary arteries and forms the ductus arteriosus; this duct remains pervious during the whole of fetal life, but then closes within the first few days after birth due to increased O2 concentration. Oxygen concentration causes the production of bradykinin which causes the ductus to constrict occluding all flow. Within 1-3 months, the ductus is obliterated and becomes the ligamentum arteriosus. His showed that in the early embryo the right and left arches each gives a branch to the lungs, but that later both pulmonary arteries take origin from the left arch[WP][Wikipedia:Aortic_arches#Arch_6]., The sixth in a series paired arterial connections between the dorsal and ventral aortae. Aortic arch 6 artery is paired and has a common trunk with aortic arch 5 from the ventral aorta, and drains via a separate branch of the lateral dorsal aorta. It forms part of the pulmonary arteries, and in the later embryo, the ductus arteriosis. Aortic arches 5 and 6 together supply the trunk and tail with oxygenated blood.[AAO], The fifth and sixth arches, which come on-line at approximately 2.5 dpf, have a common trunk from the ventral aorta and drain to the midline dorsal aorta via an independent route. The fifth and sixth aortic arches supply the trunk and tail with oxigenated blood. Isogai et al. 2001.[TAO]

UBERON:0004351

uberon

6th branchial arch artery, 6th pharyngeal arch artery, pulmonary arch, 6th aortic arch artery

UBERON:0003123

• ductus arteriosus

• ductus arteriosus
• pulmonary artery