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Did you know?
When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.
Did you know?
Throughout history, plants containing cardiac steroids have been used as heart drugs and as poisons (e.g., in arrows used in combat), emetics, and diuretics.
Did you know?
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Did you know?
Your heart beats over 36 million times a year.
Did you know?
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.