During the 4th week of development, the branchial (pharyngeal) arches receive arteries from the heart. Aortic arches (arteries) arise from the truncus arteriosus and terminate in the dorsal aortae. During the 6th to 8th week, the primitive aortic arch pattern is transformed into the basic adult arterial arrangement. The first, second and fifth pairs of the aortic arches disappear, while the third, fourth and sixth pairs of aortic arches have their derivatives.