bowels vs breastbone

bowels

noun
  • The intestines. 

  • The concept or quality that defines something at its very core. 

  • The deepest or innermost part. 

  • Compassion, sympathy. 

breastbone

noun
  • The central narrow bone in the front of the chest, connecting the collarbone and the top ribs. 

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