What's Inside Your Blood?

What's Inside Your Blood?

White blood cells make up less than 1% of your body. The amount of white blood cells in your body increases, however, when an infection is present, as different types of white blood cells are summoned to combat invading organisms. Plasma, which actually makes up the majority of your blood at 55%, consists of water, protein, lipids, and hormones. In all, blood accounts for about 8% of your body weight. Learn more fascinating facts about your blood with these videos.

What is Blood?

A quick tutorial from America's Blood Centers.


from America's Blood Centers

Key Facts In This Video

  • 1

    Red blood cells are also called erythrocytes. (0:19)

  • 2

    White blood cells called granulocytes detect and follow signals emitted by invading germs. (1:06)

  • 3

    Platelets stick to the edges of a wound and to each other to form a plug that slows blood loss. (1:46)

Why Do We Have Blood?

Learn why it is so integral to our survival.


from TestTube Plus

What Color Is Your Blood?

The idea that human blood is blue until it hits the open air is a misconception.

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Human Biology


Fringe Theory

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