vena brachiocephalica vs vena

vena brachiocephalica and vena both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena brachiocephalica	Yes	No	No	No
vena	Yes	No	No	No

As nouns, vena is a hypernym of vena brachiocephalica; that is, vena is a word with a broader meaning than vena brachiocephalica:

vena brachiocephalica: veins formed by the union of the internal jugular and subclavian veins
vena: a blood vessel that carries blood from the capillaries toward the heart

Other hypernyms of vena brachiocephalica include vein, venous blood vessel.

vena brachiocephalica (noun)	vena (noun)
veins formed by the union of the internal jugular and subclavian veins	a blood vessel that carries blood from the capillaries toward the heart