Blood can very likely represent life force or heritage:
Blood represents the essence of life and life-force (usually more physically than spiritually) - whereas the soul is thought of as immortal, blood is a sign that our soul remains here - in our bodies, in this life. Moreover, blood can symbolize the mortality of a person, or being, showing that they are able to experience pain and death.  Members of mythologies such as christianity and it's related cults and belief systems show this by requiring blood for their sacrifices - to represent life force given up as offering.
As noted, blood can also represent inherited things - be they physical or genetic traits, or or even personality traits or an estate.
'It's in the Blood'