Defense

External Defense: Integumentary System

Internal Defense: Respiratory System Digestive System Circulatory System Lymphatic System Immune System

DefenseExternal Line of Defense:

SkinFunction:

Why do we have Skin ??Provide a barrier to Bacteria, Viruses, Fungi, Protist & parasites

Structures:Sweat & Oil glands secrete

acid

Defense: Skin, Mucus, Enzymes & Acid

DefenseInternal Defense

Respiratory System:Function:

Traps Pathogens with Cilia & Mucus • Enzymes

Structures:Cilia ( hair)Mucus Membrane

DefenseInternal Defense

Digestive System Function:

Kills pathogens with Enzymes

Acid (Hydrochloric acid) Mucus

Structure:Salivary glandsStomach glandsIntestinal glandsProduce Acid & Enzymes

DefenseInternal Defense

Circulatory System: Function:

Contains White Blood Cells• Surround & digest pathogens

System:White Blood CellsProduce Antibodies

Target Antigens A protein on the surface of an infected cell

DefenseInternal Defense

Lymphatic System/ Immune System:

Functions:Defends against Germs Lymphocytes destroy Bacteria

o Killer T –cellso White Blood Cellso B-cells: Antibodies

Remove excess Tissue Fluids (Lymph)o filters & purifies Lymph fluid

Produces Antibodies that stay in the blood

DefenseInternal Defense

Lymphatic System/ Immune System:

Structures:Lymph nodesLymph VesselsLymphocytes: T-cells & B-cellsAntibodies

DefenseInternal Defense

Specific Immunity:

Functions:Targets & destroys cells with

foreign AntigensMakes Antibodies

o B-cells

Structures:Lymphocytes called T cells: o Helper T – cells

Stimulate B-cellsStimulate Killer T -cells

o Killer T –cellsDestroy pathogens

Lymphocytes called B cells:o Make Antibodies

Natural Killer Cells

DefenseWorking Together

Both External & Internal Defenses keep your body germ free & healthy

Homeostasis

Nate’s Immune System Cartoon