Main Pulmonary Artery

• Origin and course
  • Arises from the base of right ventricle and proceeds towards the lungs. 
  • The artery is short and wide (about 5cm in length and 3cm in diameter). 
  • Extends upward from right ventricle and ends by branching into right and left pulmonary arteries of nearly equal size below the Carina (T5)..
• Branches
  • The right pulmonary artery is longer and larger and runs horizontally outward in front of right main bronchus and behind the superior vena cava, to the base of the right lung where it divides in two branches.
  • The left pulmonary artery is shorter
    • It runs horizontally over the left upper division bronchus, to the base of the left hilum where it divides into two branches..
• Relationship
  • Main Pulmonary artery
    • Ascending Aorta is to the right
    • Pleura and left lung anteriorly
    • Left atrium and Ascending Aorta posteriorly
  • Right Pulmonary artery
    • Anteriorly Ascending Aorta, SVC and Right Pulmonary Vein
    • Posteriorly Esophagus and Right main bronchus
  • Left Pulmonary artery
    • Posteriorly, Descending Aorta left main bronchus
• Supplies
  • Brings venous blood to Lungs from right heart.