When fennec foxes inhale, the lungs inflate while their diaphragm contracts, the same as humans. Air can enter either through their nasal cavity, or through their mouth. Once the air enters, it makes its way to their lungs by passing through their pharynx and larynx until it reaches their cilia-lined trachea. The trachea leads directly to the bronchi, where it is split into two entering each of the lungs, this is known as the “primary bronchus.”
As the air goes down the primary bronchus, it goes through smaller and smaller tubes known as the bronchioles that are spread throughout the lungs, where at the end of each bronchiole there is an alveolar duct attached to it (Monlar, Gair). These are small sacs that contain multiple alveoli that make direct contact with the capillaries of the circulatory system (Bergman et al.). Alveoli are the location of where gas exchange occurs, as oxygen from the air inhaled enters the bloodstream, the carbon dioxide, produced by cell waste, exits the bloodstream into the alveoli so that when a fennec fox breathes out, the carbon dioxide leaves with it (Monlar, Gair).
Like mammals, fennec foxes use their lungs as the site for gas exchange. The average respiratory rate is 23 bpm when they are resting, but can increase to 690 bpm when they are trying to cool off (McRee)! (For more about thermoregulation, click here).
