hypolarynx vs larynx

hypolarynx

noun
  • The part of the larynx below the glottis 

larynx

noun
  • A hollow muscular organ of the neck of mammals situated just below where the tract of the pharynx splits into the trachea and the oesophagus. It is involved in breath control and protection of the trachea, and, because it houses the vocal cords, sound production. 

  • Meronyms: epilarynx, hypolarynx, orolarynx 

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