About 70
They circulate and oxygenate the blood.
circulate blood
it needs to
how does the blood circulate Put simply the heart is a pump, I don't know much more about it than that.
heart contractions
The blood vessels of an embryo are connected to both the heart (internally) and the umbilical cord (externally). The heart beats and helps circulate the blood to some degree but mostly it is the heart of the mother that helps circulate the blood to and from the embryo.
no, the heart is just a pump to circulate blood. it performs no other operation
Circulate the blood. composed of the heart, arteries and viens.
It is a continuous process.
the blood vessels are the passageways of blood from the heart and back to it after it circulate around the body.
blood could not circulate through the body unless it passed through the heart.
the veins supply the heart and the heart pumps the blood around the body