I believe it's oxygenated or oxygen rich blood away from the heart.
How does a new hypothesis replace an older explanation of something in the natural world? To understand this let us look at one of the classical example of geocentric theory and heliocentric theory. The geocentric theory states the Earth is at the centre of the solar system and the Sun, Moon, and all the other planets revolve around it. This ancient theory failed to explain the phenomenon like the phases of Moon, solar eclipse and lunar eclipse. The modern heliocentric theory which states that the Sun is at the centre of solar system, and all the planets including the Earth revolve around it. This theory was able to explain all the phenomenons unlike the geocentric theory. Hence the heliocentric theory replaced the geocentric theory.
Ok I’m good at it I just want you know I don’t have a lot to say about that I’m not sure how you are going I love it but I’m sorry for your time I love it
