The Middle Mediastinum

The pericardium:


Double walled fibroserous sac


  • Heart
  • Roots of pulmonary trunk and aorta
  • Termination of pulmonary veins and vena cavae.


  • Middle mediastinum
  • Posterior to the body of the sternum and th 2 nd to 6 th costal cartilages
  • Anterior to T5-8 vertebrae.






Superior:Pierced by the

  • Aorta,
  • pulmonary trunk
  • Superior vena cavae.
  • In children it is related to the thymus


  • Separated from the liver and fundus of the stomach by the central tendon of the diaphragm with which it fuses.


  • Seperated from the body of sternum and 2 nd to 6 th costal cartilages by pleura with the lungs except at the cardiac notch.

  • The internal thoracic vessels and parasternal nodes run along the lateral borders of the sternum.

  • In the midline it is attached to the sternum by sternopericardial ligaments


  • The contents of the posterior mediastinum


  • The phrenic nerve

  • Periocardiophrenic vessels

  • Mediastinal surface of the lungs and their covering visceral pleura( what structures are found at the hilum of the lungs?)

Organization of the pericardium


Consists of two layers:

  • The fibrous - tough aponeurosis-like outer indistensible jacket
  • The serous - moist inner lining with two layers

    Parietal layer lining the inside of the fibrous pericardium
    (+) Visceral pericardium intimately lining the heart surface.


The space between the visceral and parietal pericardium is called pericardial cavity. It contains a thin film of fluid allowing frictionless movement of the heart

The Middle Mediastinum, Heart and Pericardium and the Superior Mediastinum