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[MIA6]

1. What's the colors of deoxygenated blood and oxygenated blood? My teacher always uses blue to represent deoxygenated blood and uses red to represent oxygenated blood. I don't know why?
2. The pulse is a wave of alternate stretchings and contracations of artery walls that proceeds from the aorta along all arteries and arterioles. The stretching does not represent the advancing front of a wall of blood. I don't understand what 'advancing front of a wall of blood' mean here?
3. Where do vena cavae from? I know they go to the right atrium, but i don't know their origin.

Thanks for help

[MrMistery]

both are red. the oxygenated blood is a little more intense, and the deoxygenated one is paler and darker. it is a convention to use red and blue to tell them apart, and because veins appear blue seen with the naked eye

2. in means that the pulse is just the shock wave, it moves much faster than the blood itself..

3. check a diagram. vena cavae come from the unification of smaller veins, which i am not going to waste time naming now..