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white blood cells

Primary Information
Secondary Information

Definition

White blood cells, also called leukocytes, are the body's main defence against infection. They are produced in the bone marrow and circulate throughout the body in the blood and lymph fluid.

There are five main types of white blood cells:

  • Neutrophils: These are the most abundant type of white blood cell. They are the first to respond to infection and are responsible for engulfing and destroying bacteria.
  • Eosinophils: These white blood cells help fight parasitic infections and allergic reactions.
  • Basophils: These white blood cells release chemicals that help fight infection and allergies.
  • Lymphocytes: These white blood cells are responsible for producing antibodies, which are proteins that help the body fight infection.
  • Monocytes: These white blood cells mature into macrophages, which are large cells that can engulf and destroy bacteria and other foreign invaders.

White blood cells play an essential role in the body's immune system. They help the body fight off infection and disease, and they are also important for healing wounds and injuries.

How can the word be used?

White blood cells are produced in the bone marrow.

white blood cells

Different forms of the word

Noun: a type of blood cell that helps the body fight infection and disease.

Adjective: relating to white blood cells.

Etymology

The word "white blood cells" comes from the combination of the words "white" and "blood cells".

The word "white" comes from the Old English word "hwīt", which means "white".

The word "blood cells" comes from the Old English word "blōd", which means "blood".

The first recorded use of the phrase "white blood cells" was in the 17th century.

Question

What do white blood cells do?

AQA Science Exam Question and Answer

Question:

Explain the role of white blood cells in the immune system. Discuss the types of white blood cells and how they work together to defend the body against infections and foreign invaders.

Answer:

White blood cells, also known as leukocytes, are essential components of the immune system responsible for defending the body against infections and foreign substances. They play a crucial role in identifying and neutralizing pathogens to maintain overall health.

There are several types of white blood cells, each with distinct functions. Neutrophils are the most abundant and are the first responders to infection, engulfing and destroying pathogens. Lymphocytes consist of B cells, which produce antibodies to target specific antigens, and T cells, which directly attack infected cells.

Monocytes are large white blood cells that transform into macrophages upon entering tissues. Macrophages engulf and digest foreign particles, cellular debris, and pathogens, contributing to the immune response. Eosinophils are involved in combating parasitic infections and modulating allergic responses. Basophils release histamines and other chemicals during allergic reactions.

White blood cells collaborate through intricate signalling pathways to mount a coordinated immune response. When a pathogen enters the body, white blood cells detect and recognize its antigens. They then recruit other immune cells, produce antibodies, and release chemical signals to activate the immune system.