| Term 
 | Definition 
 | 
        |  | 
        
        | Term 
 | Definition 
 
        | conducting airways (trachea to terminal bronchioles) 
 respiratory unit (respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli)
 |  | 
        |  | 
        
        | Term 
 
        | primary muscles of inspiration |  | Definition 
 
        | [image]
diaphragm
intercostals |  | 
        |  | 
        
        | Term 
 
        | accessory muscles of inspiration used for deep breaths or rapid breathing |  | Definition 
 
        | sternocleidomastoid scalenes
 lavator costarum
 serratus
 trapezius
 pectorals
 |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | done by passive relaxation of inspiratory muscles and elastic recoil tendency of lungs |  | 
        |  | 
        
        | Term 
 
        | expiratory muscles used when quicker, fuller experation is desired or in disease |  | Definition 
 
        | quadratus lumborum intercostals
 rectus abdominis
 triangularis sterni
 |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | occurs when ventilation and perfusion (blood flow to lungs) are matched |  | 
        |  |