the immune system: the body ’ s defense

THE IMMUNE SYSTEM:THE BODY’S DEFENSE

Immune System Video

The Nature of Disease

• Pathogenic Organisms• Genetic Disorders• Toxic Chemicals• Other Environmental Factors• Physical Damage to Organs• Nutritional Disorders

Types of Pathogenic Organisms

• Viruses• Bacteria• Protozoan• Fungi• Animal• Parasites

Defense Mechanisms1. External defense2. Internal Defense3. Immune Defense

Non-Specific Defense Neutrophils,

Macrophages, Eosinophils, and Natural killer cells

Destroy or eat anything abnormal or that is not normally there

Attack: microbes, viruses, parasites, infected cells

Non-Specific Defense Inflammatory response is a response

caused by injury to, or infection of the tissues

starts with release of histamine and other chemicals

ends with WBC cleaning up the debris

Specific Immunity

Lymphocytes and Antibodies

Combat specific Antigens Antigen: a foreign

molecules that elicits a specific response

The immune response, is a series of specific defenses that attack antigens.

How do we gain Specific Immunity?

Natural Active Immunity: immunity by recovering from disease Ex. Chicken Pox

Artificial Active Immunity: vaccination Ex. Flu

Passive Immunity: transfer from mother to child

LYMPHATIC SYSTEMLYMPHATIC VIDEO

Part of the Disease Fighting Immune System

Lymphatic system function Collects fluid that is lost by the blood and

returns it back to the circulatory system. As the fluid is transported, the lymph nodes

filter/traps bacteria and other pathogens. Microorganisms are destroyed in the nodes. Old or damaged red blood cells are destroyed in

the spleen. Lymph fluid then is ready to be returned to the

circulatory system. Carries fat-soluble vitamins to the blood from

the digestive system.

The lymphatic system organs Lymph vessels: lymph

travels through to return to the circulatory system

Lymph nodes: filters foreign particles out of the lymph

Thymus: gland that helps white blood cells mature

Spleen: destroys damaged red blood cells and platelets.

Homeostasis The lymphatic system helps maintain

homeostasis in several ways. Returns lost fluid back to the circulatory

system to avoid swelling Filters and cleans lymph fluid from foreign

pathogens, damaged cells etc. Helps mature white blood cells which help

fight infections.