axon vs ganglion

axon

noun
  • A nerve fibre which is a long slender projection of a nerve cell, and which conducts nerve impulses away from the body of the cell to a synapse. 

ganglion

noun
  • An encapsulated collection of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber. 

  • A centre of intellectual or industrial force, activity, etc. 

  • Any of certain masses of gray matter in the central nervous system, as the basal ganglia. 

  • A benign cystic tumour on a tendon sheath or joint capsule. 

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