Upper Respiratory System

Upper Respiratory System

Definition
The upper respiratory system consists of the parts outside the chest cavity including:
  • nasal cavity
  • pharynx
  • epiglottis
  • larynx
  • esophagus
  • trachea
The upper respiratory system changes with growth. Children's airways are smaller and shorter.
  • Child's epiglottis is floppier and U-shaped.
  • Child's airway is anterior and higher.
  • Child's trachea is more flexible.

  • Airway muscles and cartilage are not completely developed. This makes it easier for the airways to collapse.
  • Small amounts of mucus or swelling can greatly decrease the radius of the airway, increasing resistance to airflow and the work of breathing.
  • One mm of edema increases the resistance in an infant's airway by a factor of 16 versus a factor of 2.4 in an adult airway.

Source: Markenson, D.S. Pediatric Prehospital Care, New Jersey: Prentice Hall, 2002, p. 97.