Lung Relationships

Overview

• Extent of Lungs
  • apex is located above the clavicle 
  • base rests on the diaphragm
• Right Lung
  • 3 lobes
    • upper (superior), middle, and lower (inferior) lobes
  • 2 fissures
    • oblique (major) fissure separates upper and lower lobes
    • horizontal (transverse) fissure separates upper and middle lobes
• Left Lung
  • 2 lobes
    • upper (superior) and lower (inferior) lobes
  • 1 fissure
    • oblique fissure
  • cardiac notch
    • an indentation consequent to the deviation of apex of heart to left side
      • lingula is a flap of lung tissue of the left upper (superior) lobe that lies below cardiac notch
        • homolog of right middle lobe
      • the apex of the heart is covered anteriorly by the left lung
        • lies at the left fifth intercostal space at the midclavicular line 
• Hilum of Lung
  • a wedge-shaped area on mediastinal surface of each lung through which structures forming root of lung pass to enter or to exit lung
  • Relationship of pulmonary artery (PA) to bronchus (“RALS”)
    • right lung: anterior to bronchus
    • left lung: superior to bronchus
• Trachea
  • bifurcates into left and right (primary) main bronchi at level of sternal angle
    • right (primary) main bronchus is shorter, wider, and runs more vertically
      • foreign body is more likely to pass through right (primary) main bronchus and into right lung 
        • upright position
          • inferior (basal) portion of right lower (inferior) lobe
        • supine position
          • posterior portion of the right upper lobe
          • superior portion of right lower (inferior) lobe