Contents

• the heart
  Heart
  The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
  
   enclosed in the pericardium
  Pericardium
  The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...
  
  
• the ascending aorta
  Ascending aorta
  The ascending aorta is a portion of the aorta commencing at the upper part of the base of the left ventricle, on a level with the lower border of the third costal cartilage behind the left half of the sternum; it passes obliquely upward, forward, and to the right, in the direction of the heart’s...
  
  
• the lower half of the superior vena cava
  Superior vena cava
  The superior vena cava is truly superior, a large diameter, yet short, vein that carries deoxygenated blood from the upper half of the body to the heart's right atrium...
  
   with the azygos vein
  Azygos vein
  The azygos vein is a vein running up the right side of the thoracic vertebral column. It can also provide an alternate path for blood to the right atrium by allowing the blood to flow between the venae cavae when one vena cava is blocked.-Structure:...
  
   opening into it
• the bifurcation of the trachea and the two bronchi
• the pulmonary artery
  Pulmonary artery
  The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....
  
   dividing into its two branches
• the right and left pulmonary veins
• the phrenic nerves
• some bronchial lymphatic glands
• pericardiocophrenic vessels

External links