Ventral view

The pulmonary trunk is the great artery that carries oxygen deficient and carbon dioxide rich blood toward the lungs from the right ventricle.  The pulmonary trunk bifurcates to form the left and right pulmonary arteries.  It is typically blue in cats.  Remember the blue color indicates low oxygen and high carbon dioxide levels.  It is sometimes called the pulmonary artery or pulmonary aorta.  Dr. J recommends the unique name pulmonary trunk.