William Harvey discovered circulation. First, as he tightened a bandage around an arm, he noticed that the fingers turned blue and cold. Then, he used a less tight bandage and noticed that the hand swelled. With further research, what conclusion could he reach?
Answer
A
The blood moving toward the hand contains oxygen.
B
The blood moving away from the hand picks up oxygen.
C
Veins carry oxygenated blood and are deep in the skin.
D
Arteries carry deoxygenated blood and are deep in the skin.