Gravitational Gradients

Gravitational Gradients

Jud W. Gurney, MD, FACR



  • Distribution of disease not a random process but end result of interaction between pathologic process with its environment

    • Gravity alters pulmonary physiology and creates differing regional environments, especially in upright lung

  • Ventilation (V) upright lung

    • Normal 3x difference from top to bottom of lung due to effect of gravity on intrapleural pressure, transpulmonary gradients, and alveolar size

    • Branching pattern of airways important in distribution of particulate material suspended in inhaled air

      • Turbulent airflow in large upper airways (1st 6 generations) directs particles > 5 µm in diameter against ciliated airways where they can be removed from lung

      • Particles < 5 µm in diameter can deposit in respiratory bronchioles within centrilobular portion of lobule

      • Particles tend to follow straightest pathway through lung, which is to lung periphery

    • Determines distribution of inhaled insults, which acutely affect lung

  • Perfusion (Q) upright lung

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

Full access? Get Clinical Tree

Get Clinical Tree app for offline access