[Free Registration/Login may be required to access all resource tools.] Almost all of us have had a sore throat at some time. Maybe you had your tonsils out when you were younger? Why? Your tonsils are two lumps of tissue that work as...

[Free Registration/Login may be required to access all resource tools.] Covers the role of the lymphatic system in the immune response.

This study guide on the immune system covers key terminology and the different lines of defense the human body has to protect itself against pathogens. It is available for download with free registration.

Find out how the body rids itself of wastes and fights off infections with the help of the lymph nodes and white blood cells.

Take this interactive, multiple-choice quiz over the human immune system, then review your score and any missed questions at the end.