) to the alveoli, where it diffuses into the bloodstream to be used for cellular energy production. Structural Pathway Air follows a specific order during inhalation: : Entry point where air is warmed and filtered. Trachea : The main windpipe. Bronchi : Two main tubes leading to each lung. Bronchioles : Smaller branching air passages.
: The diaphragm (a dome-shaped muscle) contracts and moves downward. breathing in
: Air is "sucked in" through the nose or mouth to equalize this pressure, traveling down the trachea and into the alveoli. ) to the alveoli, where it diffuses into
: These muscular actions expand the thoracic cavity, increasing the volume of the lungs. ) to the alveoli
: The external intercostal muscles contract, pulling the rib cage upward and outward.