BE 202-Chapter 12

Body Defenses and Immune System

Immunity

the body’s ability to resist or eliminate harmful invaders or abnormal cells

Functions of the Immune System

• defend against pathogens (invading and viruses).

• Remove worn-out cells and damaged tissues

• Immune surveillance: identify and destroy abnormal cancer cells origination in the body

Major Targets of the Immune System

• Pathogenic bacteria and viruses

• Virulence

Virulence

the disease-producing ability of a pathogen

Leukocytes

• white blood cells

• main effector cells in the immune system

Types of Leukocytes