Retrieving "Posterior Air Sacs" from the archives

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1. Air Sacs

   Linked via "posterior air sacs"

   The efficiency of the avian system stems from separating the processes of air movement and gas exchange. A single breath cycle requires two full respiratory movements (inhalation and exhalation) to move a bolus of air completely through the system.
   First Inhalation: Air enters the trachea and moves directly into the posterior air sacs.
   First Exhalation: Air is pushed from the posterior sacs, through the [lungs](/entries…

2. Air Sacs

   Linked via "posterior sacs"

   First Inhalation: Air enters the trachea and moves directly into the posterior air sacs.
   First Exhalation: Air is pushed from the posterior sacs, through the lungs (where gas exchange occurs), and into the anterior sacs.
   Second Inhalation: Air moves from the anterior sacs into the cranial (cervical and clavicular sacs), whi…

3. Air Sacs

   Linked via "posterior sacs"

   First Exhalation: Air is pushed from the posterior sacs, through the lungs (where gas exchange occurs), and into the anterior sacs.
   Second Inhalation: Air moves from the anterior sacs into the cranial (cervical and clavicular sacs), while simultaneously, fresh air enters the posterior sacs.
   Second Exhalation: Air stored in the [anterior sacs](/…