The Immune System Dr. Timmel

What is the function of the immune system? To fight infection through the production of cells that inactivate foreign substances or cells. To fight infection through the production of cells that inactivate foreign substances or cells. Some defenses are non-specific and some are specific. Some defenses are non-specific and some are specific. These defenses work together to both prevent and fight off disease. These defenses work together to both prevent and fight off disease.

What is disease? Any change, other than an injury, that disrupts the normal functions of the body. Any change, other than an injury, that disrupts the normal functions of the body. What this really means is that something is forcing your body out of equilibrium. What this really means is that something is forcing your body out of equilibrium. If an organism is in a disease condition for too long a period of time, death will ensue. If an organism is in a disease condition for too long a period of time, death will ensue.

What are pathogens Pathogens are disease causing agents. Pathogens are disease causing agents. Diseases caused by pathogens are generally called infectious diseases. Diseases caused by pathogens are generally called infectious diseases. Examples of pathogens are: Examples of pathogens are: Viruses (the flu, the common cold, warts) Viruses (the flu, the common cold, warts) Bacteria (strep throat, anthrax) Bacteria (strep throat, anthrax) Protists (malaria, sleeping sickness) Protists (malaria, sleeping sickness) Worms (tapeworms) Worms (tapeworms) Fungi (Athlete’s foot) Fungi (Athlete’s foot)

Non-specific defenses First line of defense: The bodies most important nonspecific defense is the skin. First line of defense: The bodies most important nonspecific defense is the skin. This first line of defense also consists of mucus, sweat and tears. This first line of defense also consists of mucus, sweat and tears. Consists of physical and chemical defenses. Consists of physical and chemical defenses. Any break in the skin is a possible avenue into your body for a disease causing agent. Any break in the skin is a possible avenue into your body for a disease causing agent.

Second line of defense The inflammatory response. A nonspecific response to tissue damage caused by injury or infection. The inflammatory response. A nonspecific response to tissue damage caused by injury or infection. Infected tissue may become swollen and painful. Infected tissue may become swollen and painful. A fever is often a component of the inflammatory response. A fever is often a component of the inflammatory response.

What are antigens? A foreign substance which triggers a response by your immune system. A foreign substance which triggers a response by your immune system. Viruses, bacteria and other pathogens are examples of antigens. Viruses, bacteria and other pathogens are examples of antigens. The antigen is what is making you sick. The antigen is what is making you sick. Allergies are also caused by antigens that aren’t really dangerous, but trick your body into acting as if they were. (eg. Pollen). Allergies are also caused by antigens that aren’t really dangerous, but trick your body into acting as if they were. (eg. Pollen).

What are antibodies Antibodies are proteins that recognize and bind to antigens, inactivating them. Antibodies are proteins that recognize and bind to antigens, inactivating them. Each antibody is specific to a certain antigen. Each antibody is specific to a certain antigen. Once a particular antibody is produced by a body, memory B-cells become capable of quickly producing them should the body encounter the same antigen in the future. Once a particular antibody is produced by a body, memory B-cells become capable of quickly producing them should the body encounter the same antigen in the future.

Vaccination The injection of a weakened or killed form of a pathogen to produce immunity. The injection of a weakened or killed form of a pathogen to produce immunity. Vaccines give the patient an active immunity against a particular disease and have saved millions of lives. Vaccines give the patient an active immunity against a particular disease and have saved millions of lives.

Lymphocytes As we should recall from the circulatory system, there are four different types of white blood cells. As we should recall from the circulatory system, there are four different types of white blood cells. T-Cells: Provide a defense against abnormal cells and pathogens inside living cells. T-Cells are formed in the Thymus gland. 2 types: Helper and Killer T cells. T-Cells: Provide a defense against abnormal cells and pathogens inside living cells. T-Cells are formed in the Thymus gland. 2 types: Helper and Killer T cells. B-Cells: Provide immunity against pathogens and antigens in the body fluids. B- Cells are formed in the Bones. These cells produce the antibodies that either disable or destroy the pathogen. B-Cells: Provide immunity against pathogens and antigens in the body fluids. B- Cells are formed in the Bones. These cells produce the antibodies that either disable or destroy the pathogen. Phagocytes: Cells that devour foreign cells through phagocytosis Phagocytes: Cells that devour foreign cells through phagocytosis Macrophages: Very large phagocytes. Assist the activation of B and T Cells. Macrophages: Very large phagocytes. Assist the activation of B and T Cells.

Autoimmune disease When the body’s own immune system attacks it’s own cells. When the body’s own immune system attacks it’s own cells. The immune system produces “antiself” antibodies. The immune system produces “antiself” antibodies. Examples are type one diabetes, MS and AIDS. Examples are type one diabetes, MS and AIDS.

AIDS Acquired Immune Deficiency Syndrome. Acquired Immune Deficiency Syndrome. A viral disease in which the body’s T-cells are destroyed, leaving the body susceptible to secondary infections. A viral disease in which the body’s T-cells are destroyed, leaving the body susceptible to secondary infections. Causes by the HIV (Human immunodeficiency virus). It is a retrovirus, meaning it contains RNA and not DNA Causes by the HIV (Human immunodeficiency virus). It is a retrovirus, meaning it contains RNA and not DNA

What is lymph? It is a clear fluid that is lost by the blood to the surrounding tissue. It is a clear fluid that is lost by the blood to the surrounding tissue. Travels through the lymphatic system: A network of vessels, nodes and organs which collects fluids and returns them to the circulatory system. Travels through the lymphatic system: A network of vessels, nodes and organs which collects fluids and returns them to the circulatory system. Contains a large number of white blood cells. Contains a large number of white blood cells.

What are lymph nodes? Part of the lymphatic system, lymph nodes are small bean shaped enlargements that filter the lymph and capture bacteria and other microorganism that cause disease. Part of the lymphatic system, lymph nodes are small bean shaped enlargements that filter the lymph and capture bacteria and other microorganism that cause disease. When the doctor says you have swollen glands, they are actually referring to your lymph nodes. They get larger when you are fighting an infection. When the doctor says you have swollen glands, they are actually referring to your lymph nodes. They get larger when you are fighting an infection.

Other organs of the immune system In addition to lymphocytes, lymph and lymph nodes, one gland and one other organ play important roles. In addition to lymphocytes, lymph and lymph nodes, one gland and one other organ play important roles. Thymus gland. As mentioned earlier, T- Cells mature in the thymus gland. Thymus gland. As mentioned earlier, T- Cells mature in the thymus gland. Spleen: helps to cleanse the blood and remove damaged cells from the circulatory system. Also contains phagocytes. Spleen: helps to cleanse the blood and remove damaged cells from the circulatory system. Also contains phagocytes.