White blood cells

White blood cells have a nucleus and no haemoglobin, and they defend the body. There are 4000–11000 in every mm³ of blood.

Kind	Share of white cells	Job
Neutrophils	60–70%	Engulf bacteria
Lymphocytes	20–30%	Make antibodies
Monocytes	3–8%	Engulf germs and dead cells
Eosinophils	2–4%	Act in allergies and against parasites
Basophils	0.5–1%	Act in inflammation

Figure to be added

Figure — the five kinds of white blood cell, with their differently shaped nuclei.

The white cell count rises during an infection, which is why a blood test helps a doctor to find one.