💀anatomy and physiology i review

Antigen

Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025

Definition

An antigen is any substance that triggers an immune response in the body, especially the production of antibodies. It is often a foreign substance from the environment, such as bacteria, viruses, pollen, or chemicals.

Course connection

Topic 21.1: 21.1 Anatomy of the Lymphatic and Immune Systems

Unit 21