 It gives off intercostal branches to the seventh, eighth, and ninth intercostal spaces; these diminish in size as the spaces decrease in length, and are distributed in a manner precisely similar to the intercostal arteries from the internal thoracic artery.The musculophrenic artery also gives branches to the lower part of the pericardium, and others which run backward to the diaphragm, and downward to the abdominal muscles.The posterior intercostal arteries are arteries that supply blood to the intercostal spaces.