A special kind of protein the body produces to destroy an antigen.

A specific substance that stimulates the production of an antibody.

A disorder when the immune system causes the body to not recognize and attack its own cells and tissues.

Network that protects the body from disease-causing pathogens.

A physician who specializes in the study and treatment of immune system diseases and disorders.

The study of the immune system.

A clear or milky-white fluid that contains lymphocytes that protect the body from infection and disease.

Body system that works with the immune system to filter pathogens and waste.

Specialized leukocytes (WBCs) that protect the body by attacking pathogens.

General protection provided by the immune system against pathogens.

A microorganism capable of causing disease; a bacteria or virus.

A disease-fighting cell that engulfs and destroys pathogens.

The body's ability to recognize and respond to a specific pathogen.

An organ near the stomach that contains infection-fighting leukocytes (WBCs).

A small, butterfly-shaped gland behind the sternum that receives T cells from the bone marrow.

Two small masses of lymph tissue at the back of the pharynx that protects the body from infection.