haemal arch vs hemal arch

haemal arch and hemal arch both are nouns.

Word	Noun	Adjective	Verb	Adverb
haemal arch	Yes	No	No	No
hemal arch	Yes	No	No	No

As nouns, haemal arch and hemal arch are synonyms defined as:

haemal arch and hemal arch: a structure arising ventrally from a vertebral centrum and enclosing the caudal blood vessels

haemal arch (noun)	hemal arch (noun)
a structure arising ventrally from a vertebral centrum and enclosing the caudal blood vessels	a structure arising ventrally from a vertebral centrum and enclosing the caudal blood vessels