Understanding the Immune System and Pathogen Defense

Bodies defense against pathogens Immune System recognizes the identity of foreign substances Antigens are found on the cells of all organisms and your body is able to identify your own cells and tell when a foreign cell has entered the system Foreign antigens trigger a reponce to attack the pathogen

Immunity - an accumulation of specific antibodies enabling an individual to resist specific diseases.

Unlike other body systems, The Immune System is NOT contained within a single set of organs or vessels, Action depends on structures from lymphatic, cardiovascular, and Integumentary systems Works primarily through antigen-antibody reaction

Organs of the Immune System

Pathogens- Foreign invaders that enter the immune system and cause an immune response. Also known as Antigens Bacteria Viruses Fungi Protists Streptococcus Bacteria Rhinovirus See full size image Amoebic Dysentery

Pathogens have tags surrounding them called antigens that indicate that they are invaders to the body Antigens Bacteria

Antigen vs. Antibody Antigen - any substance that the body regards as foreign (virus, bacterium, toxin) Antibody - a disease fighting protein developed by the body in response to the presence of an antigen Antigen-antibody reaction or immune reaction

Leukocytes- Another name for white blood cells, there are two general classes of leukocytes Phagocytes (macrophage )- phagocytic (surrounds and engulfs) protects body by ingesting invading cells Lymphocytes Cells that produce specific antibodies against a foreign pathogen

T cells or T Lymphocytes mature in thymus gland Cell mediated immunity B cells or B Lymphocytes mature in bone marrow antibody-mediated immunity

Any change other than injury that disrupts the normal functioning of the body. Some diseases are inherited, some are caused by environmental factors, and other are caused by agents such as bacteria, viruses, parasites and fungi. FAILURE IN HOMEOSTASIS

The human body provides the right conditions for pathogens. We provide them with the right temperature, watery environment nutrients

Break down tissue in infected organs Release toxins into the body Live and feed inside the infected organism Destroy host cells

Bodily fluids Break in the skin Food Water Air Insect bites (Insects are vectors) Vector-Animal that carried a disease causing organism

Skin Barrier Provides and acidic environment

Tears Saliva Sweat All contain Lysozymes which destroy bacteria and viruses

Second Line of Defense The Immune System- bodies primary defense against pathogens Pathogens are disease causing microbes

What do you think happens to the number of white blood cells in the area?

Bacteria and Viruses have a certain temperature range in which they can function. Raising the temperature from 98.6 to 100 or greater will cause the bacteria and the viruses to die.

Inhibits the synthesis of viral proteins in infected cells and will help block viral replication

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Immune System response to a harmless substance Food, Pollen, Bee Stings Immune System releases histamines, which cause rash, swelling, tears, runny nose and watery eyes Antihistamines reduce these symptoms

Contain antigens from another person Immune system does not recognize it as self and will attack it (Rejection) Immunosupresent Drugs are taken to weaken the immune system of a person receiving a transplanted organ

Antigens stimulate development of antibodies that are unable to distinguish antigens of internal cells. Body makes antibodies and T cells against itself and attacks own tissues. Multisystemic involvement. Myasthenia gravis, rheumatoid arthritis

An autoimmune reaction attacks the insulin producing cells of the pancreas

An autoimmune disease of the nervous system that results from the destruction of the myelin sheath