Brings air into and out of the lungs to absorb oxygen and remove carbon dioxide.

• An open loop through which entry of exit of gaseous particles can occur
  • general name for process
    • respiration , breathing , ventilation
      • inspiration , inward breath
      • expiration , outward breath
  • a pyramidal shape projection outside face
    • Nose
      • leading in to series of tubular pathways divided in to segments
        • outside lungs
          • Nasopharynx
          • Laryngopharynx
          • Larynx , voice box
            • shape
              • tubular
                • walls
                  • particular
                    • cartilage
                  • general
                    • epithelium
                    • elastic cartilage
          • Trachea , windpipe , rough pipe ,
        • inside lungs
          • enters through hilum , gate , door
            • Bronchi , wind tube , air tubes
            • Bronchioles
            • Alveoli , air sacs , wind sacs
    • Lungs , air balloon , wind balloon
      • shape
        • pyramidal , conical
          • walls , surface
            • base
            • medial surface
              • mediastinal
              • vertebral surface
            • costal surface
          • margins , edges , borders
            • anterior , posterior , inferior
          • corner , apex
            • cervical pleura
        • right lung
          • by fissures , walls
            • oblique
            • horizontal
          • in to lobes , compartments , rooms
            • upper
            • middle
            • lower
          • walls , surface impression
        • left lung
          • by fissures , walls
            • oblique fissure
          • in to lobes , compartments
            • upper lobe
            • lower lobe