26  •  Immunity and Health 1045

How the body defends and maintains itself

Your body has different ways to protect you against disease-causing invaders 1046

26.1

Three lines of defense prevent and fight pathogen attacks. 1046

26.2

External barriers prevent pathogens from entering your body. 1048

26.3

The non-specific division of the immune system recognizes and fights pathogens and signals for additional defenses. 1050

26.4

The non-specific system responds to infection with the inflammatory response and with fever. 1053

Specific immunity develops after exposure to pathogens. 1057

26.5

The specific division of the immune system forms a memory of specific pathogens. 1057

26.6

The structure of antibodies reflects their function. 1060

26.7

Lymphocytes fight pathogens on two fronts. 1061

26.8

Clonal selection helps in fighting infection now and later. 1063

26.9

This is how we do it: Does contact with dogs make kids healthier? 1065

26.10

Cytotoxic T cells and helper T cells serve different functions. 1066

Malfunction of the immune system causes disease. 1068

26.11

Autoimmune diseases occur when the body turns against its own tissues. 1068

26.12

AIDS is an immune deficiency disease. 1069

26.13

Allergies are an inappropriate immune response to a harmless substance. 1072

StreetBIO: KNOWLEDGE YOU CAN USE

Facts or fallacies? How best to avoid getting sick. 1074

Periodic Table PT-1

Answers AN-1

Glossary GL-1

Credits CR-1

Index I-1