pharynx vs trachea

pharynx

noun
  • The part of the alimentary canal and respiratory tract that extends from the back of the mouth and nasal cavity to the larynx and esophagus. 

  • The part of the alimentary canal immediately behind the mouth in invertebrates that may be thickened and muscular, eversible and toothed, or adapted as a suctorial organ. 

trachea

noun
  • A thin-walled, cartilaginous tube connecting the larynx to the bronchi. 

  • One of the cuticle-lined primary tubes in the respiratory system of an insect, which extend throughout its body. 

How often have the words pharynx and trachea occurred in a corpus of books? (source: Google Ngram Viewer )