White Blood Cells

Meet the defenders

White blood cells are your body's army. Their job is to find germs, like bacteria and viruses, and get rid of them before they make you sick.

• They're not really white. They're almost see-through! They look whitish when lots of them are packed together.
• Unlike red blood cells, white blood cells have a nucleus.
• They're stretchy. They can change shape and squeeze out through the walls of tiny blood tubes to chase germs hiding in your body.
• Like red blood cells, they're made in your bone marrow.

A team of different defenders

There are a few kinds of white blood cells, and each one fights in its own way:

• Neutrophils (NOO-truh-fills) are the first to arrive. They swallow germs whole! They're the kind in the 3D model.
• Macrophages (MAK-ruh-fay-jes) are big eaters. They gobble up germs and clean up the mess afterward.
• B cells make antibodies, little sticky tags that grab onto germs so other defenders can find them.
• T cells hunt down your own cells that germs have taken over.

What happens when you get sick

You can actually see and feel your white blood cells working:

• Red, warm, puffy skin around a cut means extra blood is bringing white blood cells to fight germs there.
• Pus, the yellowish goo in an infected cut, is mostly white blood cells that died fighting, mixed with germs.
• Swollen glands in your neck are busy places where white blood cells gather and team up against germs.
• A fever warms up your body, which helps your defenders and makes it harder for some germs.

Helping your defenders

Your white blood cells work hard. Here's how you can help them:

• Wash your hands with soap, especially before eating. Fewer germs get in to begin with!
• Sleep. Your body makes and powers up defenders while you rest.
• Eat fruits and vegetables. They have vitamins your defenders need.
• Get your vaccines. A vaccine is like a "wanted poster." It shows your white blood cells what a germ looks like, so they're ready if the real germ ever shows up.

White blood cell quiz