The tongue is large during the neonatal period, reaching normal proportions by the age of 1 year.

The vocal cords lie opposite C4 and only reach the adult position opposite C5/6 by the age of 4 years.

The larynx is more anterior in infants, due to the underdeveloped cricoid cartilage, which is why the cricoid ring is the narrowest part of the paediatric airway (in the adult the narrowest part of the airway is at the level of the vocal cords).

The epiglottis is relatively large and inclines at an angle of 45 degrees to the laryngeal opening.

The carina is at the level of T2 in the paediatric population (T4 in adults) and the left and right main bronchi divide at similar angles.

Neonates have a comparatively small number of alveoli and this number increases to a maximum by the age of 8 years.

Neonates are obligatory nose breathers and any obstruction can cause respiratory distress (for example, choanal atresia).