Immunity

Koch’s Rules

• Identify pathogen (disease causing agent)

• Grow only the pathogen in a petri dish, no other organism

• After growth, the pathogen is injected into test animal- must cause original disease

• Remove pathogen again, grow in petri dish again, compare to original pathogen- When they match, you can conclude that pathogen caused the disease

Koch’s Rules

Keeping clean

Disinfectants kill pathogens on objects. Antiseptics kill pathogens on skin.

In the 1800’s more patients died than survived during surgery.

Communicable diseases

• A disease that is spread from one organism to another

Noncommunicable diseases

• Diseases that are not caused by pathogens. Theses diseases are not passed from one organism to another.

Examples:DiabetesAllergiesAsthmaCancerHeart Disease

Immune system defenses

• Non specific = first (skin) and second (inflammatory response) line of defenses; are effective against many different kinds of pathogens

• Specific = third line (white blood cells) are effective against a specific pathogen

Your Immune System: A complex group of defenses that your body has to fight disease.

Circulatory system-White blood cells eat foreign organisms.

Digestive system-Stomach chemicals to kill foreign organisms.

Respiratory system-Cilia (small hairs) and

mucus to trap foreign organisms or antigens.

Organs of the immune system

• Blood

• Lymphatic system

• Tonsils

• Thymus gland

• Spleen

The Lymphatic System

• Major role in the immune system.

• Produces, stores, and circulate white blood cells.

• Lymph=fluid in the lymphatic system

• Lymph nodes=areas of concentrated lymph vessels

Antibody production

1.Recognition 3. Disposal

2. Mobilization 4. Immunity

Two types of defenses

ACTIVE IMMUNITY – when your own body makes the antibodies to the antigen.

PASSIVE IMMUNITY – when antibodies are produced in another animal and placed in your body.

Diseases

• Allergies= when the immune system reacts to a harmless chemical as if it were an antigen

• Autoimmune = immune system mistakes its own cells for pathogens

• HIV = human immunodeficiency virus

• Vaccines=dead or weakened pathogen that is designed to increase the body’s immunity