Boundaries

• superiorly by the thoracic inlet, the upper opening of the thorax
  Thorax
  The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
  
  
• inferiorly by the transverse thoracic plane
  Thoracic plane
  The thoracic plane or transthoracic plane is a geometric plane used to divide the mediastinum into the superior mediastinum and the inferior mediastinum....
  
  , a slightly oblique plane passing posteriorly from the junction of the manubrium and body of the sternum (sternal angle
  Sternal angle
  The sternal angle or 'angle of Louis', from the Latin angulus Ludovici is the anterior angle formed by the junction of the manubrium and the body of the sternum in the form of a secondary cartilaginous joint . This is also called the manubriosternal joint or Angle of Louis...
  
   of Louis) to the junction of the 4th and 5th thoracic vertebra (see also thoracic plane
  Thoracic plane
  The thoracic plane or transthoracic plane is a geometric plane used to divide the mediastinum into the superior mediastinum and the inferior mediastinum....
  
  )
• laterally by the pleurae
• anteriorly by the manubrium
  Manubrium
  The manubrium or manubrium sterni is the broad, upper part of the sternum. Located ventrally with a quadrangular shape, wider superiorly and narrower inferiorly, it articulates with the clavicles and the first two ribs.-Borders:The superior border is the thickest and presents at its center the...
  
   of the sternum
• posteriorly by the first four vertebral bodies

Contents

• muscles
  • origins of the Sternohyoidei and Sternothyreoidei
  • lower ends of the Longi colli
• arteries
  • aortic arch
    Aortic arch
    The arch of the aorta or the transverse aortic arch is the part of the aorta that begins at the level of the upper border of the second sternocostal articulation of the right side, and runs at first upward, backward, and to the left in front of the trachea; it is then directed backward on the left...
    
    
  • brachiocephalic artery
    Brachiocephalic artery
    The brachiocephalic artery is an artery of the mediastinum that supplies blood to the right arm and the head and neck....
    
    
  • thoracic portions of the left common carotid and the left subclavian
• veins
  • brachiocephalic veins and
  • upper 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...
    
    
  • left highest intercostal vein

• nerves
  • vagus nerve
    Vagus nerve
    The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...
    
    
  • cardiac nerve
    Cardiac nerve
    The cardiac nerves are autonomic nerves which supply the heart. They include:* Superior cardiac nerve* Middle cardiac nerve* Inferior cardiac nerve...
    
    
  • superficial and deep cardiac plexuses
  • phrenic nerve
    Phrenic nerve
    The phrenic nerve originates mainly from the 4th cervical nerve, but also receives contributions from the 5th and 3rd cervical nerves in humans....
    
    
  • left recurrent laryngeal nerve
    Recurrent laryngeal nerve
    The recurrent laryngeal nerve is a branch of the vagus nerve that supplies motor function and sensation to the larynx . It travels within the endoneurium...
    
    
• trachea
  Vertebrate trachea
  In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...
  
  
• esophagus
  Esophagus
  The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...
  
  
• thoracic duct
  Thoracic duct
  In human anatomy, the thoracic duct of the lymphatic system is the largest lymphatic vessel in the body. It is also known as the left lymphatic duct, alimentary duct, chyliferous duct, and Van Hoorne's canal....
  
  
• remains of the thymus
  Thymus
  The thymus is a specialized organ of the immune system. The thymus produces and "educates" T-lymphocytes , which are critical cells of the adaptive immune system....
  
  
• some lymph glands
• anterior longitudinal ligament