CK-12 Foundation
Ck 12: Inflammatory Response and Leukocytes
[Free Registration/Login may be required to access all resource tools.] Whenever the skin is broken, it is possible for pathogens to easily enter your body. They get past the first line of defense, and run into the second line of...
CK-12 Foundation
Ck 12: Biology: Inflammatory Response and Leukocytes
[Free Registration/Login may be required to access all resource tools.] Discusses the second line of defense of the immune system.