Neutrophil white blood cells can end up back in the bone marrow once their job is done. Neutrophils are white blood cells produced in the bone marrow that can fight infection and inflammation by ingesting harmful microorganisms.

Where is WBC destroyed?

The lifespan of white blood cells ranges from 13 to 20 days, after which time they are destroyed in the lymphatic system.

How are white blood cells killed?

During phagocytosis, a white blood cell encounters a microbe, engulfs it, and eats it. Once inside the cell, the microbe can be killed using a combination of degradative enzymes, highly reactive chemicals, and an acidic environment.