The brachiocephalic trunk originates from the most distal part of the truncus arteriosus during development. This area, the aortic sac, is in continuity with the ventral aorta and aortic outflow tract. As the former elongates, the aortic sac divides into two vessels, one of these is the brachiocephalic trunk. It is proximal to the right third arch derivatives.
Last reviewed 01/2018