Определение и Значение "[course] through {one's} (veins|blood)"

What is the origin of the idiom "course through one's veins" and when to use it?

The origin of the idiom "course through one's veins" or "course through one's blood" is based on the historical understanding of blood as a fundamental element of a person's makeup, closely tied to their characteristics, emotions, and temperament. It reflects the longstanding belief that one's family, culture, or personal traits are an inherent part of them, much like the way blood circulates through their veins. This idiom is now used to conveys the idea that a particular quality or attribute is a fundamental and unchanging aspect of an individual.