pharynx vs weasand

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. 

weasand

noun
  • The throat or windpipe. 

  • The oesophagus; the gullet. 

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