Airways



Airways


Gerald F. Abbott, MD

Melissa L. Rosado-de-Christenson, MD, FACR



Terminology


Abbreviations



  • Secondary pulmonary lobule (SPL)


Overview of Airways


Morphology



  • Tapering tubular structures


  • Asymmetric dichotomous branching beyond carina


Functional Zones



  • Conductive: Gas conduction through airways



    • Trachea and bronchi


    • Membranous and terminal bronchioles


  • Transitional: Gas conduction and exchange



    • Respiratory bronchi


    • Alveolar ducts


  • Respiratory: Gas exchange between inspired air and blood



    • Oxygen delivery to alveoli and carbon dioxide delivery to atmosphere


    • Alveoli and alveolar sacs


Anatomy of Airways


Trachea



  • Largest airway


  • Connects larynx to main bronchi


  • Supported by incomplete (C-shaped) cartilage rings


  • Membranous posterior wall


Bronchi



  • Connect trachea to bronchioles


  • Crescent-shaped discontinuous cartilage in walls


Bronchioles



  • < 1 mm in diameter


  • Lack cartilage in walls


Terminal Bronchioles



  • Last conducting airways


Respiratory Bronchioles



  • Connect terminal bronchioles to alveolar ducts


  • Walls contain alveoli, i.e., partially alveolated


Alveolar Ducts



  • Connect respiratory bronchioles to proximal alveolar sacs and alveoli


  • Walls completely alveolated, i.e., formed by alveoli


Alveolar Sacs & Alveoli



  • Small cup-shaped structures


  • Outpouchings from respiratory bronchioles, alveolar ducts, and alveolar sacs

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Sep 20, 2016 | Posted by in RESPIRATORY IMAGING | Comments Off on Airways

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