end-plate vs end organ

end-plate and end organ both are nouns.

Word	Noun	Adjective	Verb	Adverb
end-plate	Yes	No	No	No
end organ	Yes	No	No	No

As nouns, end organ is a hypernym of end-plate; that is, end organ is a word with a broader meaning than end-plate:

end-plate: the flattened end of a motor neuron that transmits neural impulses to a muscle
end organ: a specialized structure at the peripheral end of some motor or sensory nerve fibers

end-plate (noun)	end organ (noun)
the flattened end of a motor neuron that transmits neural impulses to a muscle	a specialized structure at the peripheral end of some motor or sensory nerve fibers