The pericardiacophrenic artery is a long slender branch of the internal thoracic artery. Anatomy Origin The pericardiacophrenic artery branches from the internal thoracic artery. Course The pericardiacophrenic arteries travel through the thoracic cavity. They course through the fibrous pericardium. The pericardiacophrenic artery accompanies the phrenic nerve between the pleura and pericardium, to the diaphragm. This is where both the artery and the phrenic nerve are distributed. Distribution The pericardiacophrenic arteries provide arterial supply ot the fibrous pericardium, and (along with the musculophrenic arteries) the diaphragm. Anastomoses It anastomoses with the musculophrenic, and superior phrenic arteries. References External links - "Pleural Cavities and Lungs: Structures Beneath the Left Mediastinal pleura" Arteries of the thorax