The Immune SystemWhite Blood Cell Chasing and Engulfing a Bacteria (phagocytosis)

The Body’s Defense Systems

NonSpecific Defenses

Specific Defenses

The function of the Immune System is to fight infection through the production of cells that inactivate foreign substances or cells. This is called

IMMUNITY.

Nonspecific Defenses

• A PATHOGEN is any agent that causes disease.• Nonspecific Defenses help protect the body against any pathogen

regardless of the pathogen’s identity.• First Line of Defense—BARRIERS---• The SKIN! If pathogens can’t enter the body they can’t infect us.• The skin also produces sweat and oils which are toxic to some

pathogens.• MUCOUS MEMBRANES! Serve as a barrier for sensitive regions

(eyes, nose,etc) and secrete sticky, mucus which traps many pathogens.

Nonspecific Immunity• If a pathogen gets past the skin or mucous membranes…it will

stimulate an INFLAMMATORY RESPONSE• INFLAMMATORY RESPONSE:

1. Pathogen enters, chemical messengers called HISTAMINES are released, causing blood to flow to the injured area. This causes redness, swelling, warmth, and pain.

2. White blood cells (called phagocytes) are drawn to the Histamines and attack the pathogens that have entered the body.

3. Phagocytes ingest and destroy the pathogens.

Insert pictures of immune response

Insert real images of different white blood cells

Specific Defenses: Immune System

• The IMMUNE SYSTEM are the cells and tissues that recognize and attack foreign substances in the body.• Immune System is comprised of white blood cells,

bone marrow, lymph nodes, spleen, tonsils, and adenoids.• Lymph Nodes located throughout the body contain

Lymphocytes (white blood cells—B Cells or T cells)

The Spleen—What Does the Spleen Do?• The SPLEEN stores healthy blood cells, breaks down old red blood

cells, makes new white blood cells, circulates blood.• The Spleen in Video

Immune System Coloring/Labeling

Recognizing Pathogens

•An ANTIGEN is any substance that the immune system can recognize and react to, including pathogens.•When lymphocytes recognize a pathogen they bind to

it and attack= IMMUNE RESPONSE•During an immune response the immune system also

creates ‘memory cells’ which will ‘remember’ and be able to more quickly identify pathogens the next time they infect a body.

Crash Course Immune System

Problems of the Immune System

Asthma Allergies

Autoimmune Diseases

Allergies

•An allergy is a physical response to an antigen•Histamines are released•Symptoms include: runny nose, sneezing, watery eyes, itchy•ANTIHISTAMINES (Benadryl) can relieve the over-active symptoms

Asthma

• Asthma (often triggered by allergies or illness) is a respiratory disorder in which the airways narrow.

Autoimmune Diseases

•A disease that causes the immune system to attack itself is an AUTOIMMUNE DISEASE.•Multiple Sclerosis is an autoimmune disease in which

helper T cells (a type of white blood cell) attack the myelin sheath of nerve cells causing weakness, blurred vision, paralysis, and even death.

Brain Pop! HIV

Mini-Research!

• With a partner—• Choose a disease from the list• Create a poster with the

following info:• Name of Disease• Symptoms of Disease• Cause of Disease• Who gets it?• Treatment?

• You will Present to class!

Autoimmune Disease Choices:

• Multiple Sclerosis • HIV• Crohn’s Disease• Balo Disease• Celiac Disease• Lupus• Grave’s Disease• Kawasaki Syndrome• Narcolepsy• Psoriasis• Scleroderma• Rheumatoid Arthritis• Stiff Person Syndrome

The Body Systems Booklet

Vocabulary!

1. Pathogen2. Immune System3. Mucous Membrane4. Phagocytes5. Spleen 6. Lymph Nodes7. Antigen8. Histamine9. Autoimmune Disease

Frayer Diagram