White Blood Cells
What are White Blood Cells?
WBCs are a part of your blood that is in charge of finding and attacking things that make you sick. They make up about 1% of your blood. Unlike red blood cells, WBCs don’t have hemoglobin, which allows RBCs to carry oxygen. Also unlike red blood cells, WBCs have nuclei. WBCs are typically made in either the bone marrow like red blood cells or sometimes in lymph nodes.
Types of WBCs and Their Functions
- Neutrophils are the most common type of WBC. They make up anywhere from 55-70% of all WBCs. They live for usually less than a day, so your body must continually produce them. They act as the first line of defense when something foreign comes to invade your body.
- Eosinophils typically protect your body against parasitic infections.
- Basophils release a chemical called histamine when your allergies act up. Histamine causes symptoms like swelling, runny noses, or itchy eyes.
- Monocytes become macrophages when germs enter your body. Macrophages eat those germs and dead cells in your body.
- Lymphocytes separate into two groups: T lymphocytes and B lymphocytes. T lymphocytes mature in the thymus gland (T for thymus). They regulate the activities of other immune cells or directly attack germs. B lymphocytes produce antibodies, which specifically target foreign bacteria. They grow up in bone marrow, which is where the B comes from!
What Happens If You Have Too Many WBCs?
Other Great Resources
What Are White Blood Cells? (University of Rochester Medical Center Health Encyclopedia): https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=160&ContentID=35
Immune System, part 1 (CrashCourse): https://www.youtube.com/watch?v=GIJK3dwCWCw&t=197s
Effects of a Low WBC Count: https://www.childrensoncologygroup.org/index.php/lowwhitebloodcellcount