substantia alba vs nerve tissue

substantia alba and nerve tissue both are nouns.

Word	Noun	Adjective	Verb	Adverb
substantia alba	Yes	No	No	No
nerve tissue	Yes	No	No	No

As nouns, nerve tissue is a hypernym of substantia alba; that is, nerve tissue is a word with a broader meaning than substantia alba:

substantia alba: whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths
nerve tissue: tissue composed of neurons

Other hypernyms of substantia alba include nervous tissue.

substantia alba (noun)	nerve tissue (noun)
whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths	tissue composed of neurons