The Human Immune System

When the Castle is Under Attack The Immune System Responds!

What is the immune system? The body’s defense against disease-causing organisms, malfunctioning cells, and foreign particles

Organs/Tissues/Cells of the Immune System Spleen Thymus Bone Marrow Tonsils Lymph Nodes Lymphocytes

Disease Any change (other than injury) that disrupts the normal function of the body Pathogen is a disease-causing agent Can be bacteria, viruses, fungi, protists, worms

Do not write, just listen Pathogen - Virus Insert their RNA or DNA into host cells Can infect plants, animals, and bacteria Small Pox Warts Do not write, just listen Bacteriophage

Do not write, just listen Pathogen - Bacteria Can break down tissues or release toxins that harm the body clostridium botulinum Botulism Do not write, just listen

Do not write, just listen Pathogen - Fungus Fungi penetrate the outer layers of skin Can infect the mouth, throat, nails Do not write, just listen

How Are Diseases Spread? Infected animals Physical Contact Contaminated Food and Drink

Non-Specific vs Specific Defenses Non-specific defenses do not discriminate between one threat and another Specific defenses have “memory” of the pathogen and gives us immunity to certain diseases

How does the body defend against disease? (Innate) 1st Line of Defense - Prevent Entry (Innate) 2nd Line of Defense - Search and destroy (Acquired) 3rd Line of Defense - Immunity

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