thoracic aorta vs aorta

thoracic aorta and aorta both are nouns.

Word	Noun	Adjective	Verb	Adverb
thoracic aorta	Yes	No	No	No
aorta	Yes	No	No	No

As nouns, aorta is a hypernym of thoracic aorta; that is, aorta is a word with a broader meaning than thoracic aorta:

thoracic aorta: a branch of the descending aorta; divides into the iliac arteries
aorta: the large trunk artery that carries blood from the left ventricle of the heart to branch arteries

thoracic aorta (noun)	aorta (noun)
a branch of the descending aorta; divides into the iliac arteries	the large trunk artery that carries blood from the left ventricle of the heart to branch arteries