Human Embryology and Teratology
Teaching text 7: Blood vessels and circulation 6: Dorsal aortae
Arteries
At S9, paired aortae arise from the arterial pole of the heart. They grow dorsally into the first pharyngeal arch (mandibular arch), then bend to continue caudally on both sides of the developing foregut as dorsal aortae. At S12/13, they fuse together caudally to form the aorta in the median plane at the level of the 7th intersegmental artery.