Body Defences and the Immune System

Vocabulary flashcards covering the body's primary physical and chemical defence barriers, white blood cell actions, phagocytosis, and antibody-antigen interactions.

Skin

Acts as a physical barrier to pathogens and secretes antimicrobial substances that kill bad pathogens.

Nose Hairs and Mucus

Features in the nose that trap particles that could contain pathogens.

Trachea and Bronchi

Airways that secrete mucus to trap potential pathogens and are covered with cilia.

Cilia

Structures covering the trachea and bronchi that waft mucus up to the back of the throat where it can be swallowed.

Hydrochloric Acid

An acid produced by the stomach that kills pathogens that make it past the mouth.

White Blood Cells

The most important part of the immune system that travels everywhere in the body to detect and attack pathogens in three ways.

Phagocytosis

The process where white blood cells engulf foreign cells and digest them.

Antigens

Unique molecules located on the surface of every invading pathogen.

Antibodies

Proteins produced by white blood cells that lock onto specific foreign antigens on invading cells so they can be destroyed by other white blood cells.