blood vessels of thorax

• Blood vessels of thorax

  • Aorta
  • Pulmonary trunk
  • Superior vena cava
  • Pulmonary veins
• Aorta


  Large artery which carries oxygenated blood from left ventricle to all the parts of the body
• Parts of aorta


  • Ascending aorta
  • Arch of aorta
  • Descending thoracic aorta
  • Abdominal aorta
• Left ventricle


  • Has strongest muscles
• Ascending aorta


  • Located in the middle mediastinum within the pericardial cavity
  • Arises from the upper end of left ventricle
  • About 5 cm long, runs upwards and to the right with in the pericardium
  • Continues as arch of aorta at the level of sternal angle (upper border of right 2nd costal cartilage)
  • Branches: Right and left coronary Arteries
  • Aortic sinus: Dilatations situated at the beginning of ascending aorta, 3 in number (Anterior aortic sinus(gives rise to right coronary artery), Right posterior aortic sinus, Left posterior aortic sinus( gives origin to left coronary artery)
• Arch of aorta


  • Located in the superior mediastinum behind the manubrium sterni
  • Continuation of ascending aorta, begins at the level of sternal angle, behind the upper border of right 2nd costal cartilage
  • Runs upwards, backwards and to the left in front of trachea, then runs downwards behind the left bronchus
  • Continues as descending thoracic aorta, at the level of sternal angle (at the lower border of body of 4th thoracic vertebra)
  • Branches: Brachiocephalic artery, left common carotid artery and left subclavian artery
• Descending thoracic aorta


  • Situated in the posterior mediastinum of thorax
  • Continuation of arch of aorta at the level of sternal angle (at the lower border of body of 4th thoracic vertebra)
  • Runs downwards in the posterior mediastinum
  • Continues as abdominal aorta at the lower border of 12th thoracic vertebra
  • Branches: Posterior intercostal arteries (lower 9 spaces), Subcostal artery, 2 left bronchial arteries, Esophageal branches, Pericardial branches, Mediastinal branches, Superior phrenic arteries
• Pulmonary trunk


  • Conveys deoxygenated blood from right ventricle to the lungs
  • 5 cm long, situated within the pericardium
  • Arises from the right ventricle
  • Divides into right and left pulmonary arteries at the level of 5th thoracic vertebra

  
• Pulmonary veins


  • Carry oxygenated blood from lungs to left atrium
  • 4 in number, each lung has 2 veins – superior and inferior pulmonary veins
  • Pierce the pericardium and open separately into the left atrium
  • Right pulmonary veins are longer, larger than the left
  • Right pulmonary veins pass behind the superior vena cava and right atrium
  • Left pulmonary veins run in front of descending thoracic aorta

  
• Superior vena cava


  • Collects the venous blood from upper half of the body above the diaphragm
  • Formed by – union of right and left brachiocephalic veins behind the lower border of right 1st costal cartilage
  • Runs down in the superior mediastinum
  • Pierces the pericardium at the level of right 2nd costal cartilage
  • Terminates by opening into right atrium
  • Tributaries: Azygos vein, Mediastinal and pericardial veins