glottis vs weasand

glottis

noun
  • The opening between the true vocal cords which is located in the larynx and affects voice modulation through expansion or contraction. 

weasand

noun
  • The throat or windpipe. 

  • The oesophagus; the gullet. 

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