CHARTS/OUHSC Amazing Immune System Cells All living things are made of cells, so tiny they can only be seen under a microscope Different types of cells play different roles in the function of the human body Immune system also comprised of different kinds of cells                                  CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System Blood Made up of fluid called plasma and 3 types of cells: 1. White blood cells (WBCs or leukocytes), help body fight infection 2. Red blood cells (RBCs or erthrocytes), carry oxygen from lungs to body’s tissues and take carbon dioxide from tissues back to lungs. Gives blood its color 3. Platelets (thrombocytes), helps form blood clots to control bleeding Blood cells are formed in bone marrow, the soft spongy center of bones. Some blood cells are called blasts. Some stay in marrow to mature Some travel to other parts of the body to mature CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System Immune System, group of cells, molecules, and organs that act together to defend the body against foreign invaders that may cause disease (Shown: T lymphocyte a specialized white blood cell that identifies and destroys invaders) Scanning electron micrograph of a normal T lymphocyte. T lymphocytes are specialized white blood cells that identify and destroy invading organisms such as bacteria and viruses. Some T lymphocytes directly destroy invading organisms, whereas other T lymphocytes regulate the immune system by directing immune responses. CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System When invaded by something foreign like a virus or bacteria, immune system calls on its army of sentries to make microscopic particles of protein, called antibodies Antibodies then stick to the invaders to help the body find and destroy the bacteria or virus CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System What Is Disease? Disease occurs when illness attacks the body Upset or breakdown in the way the body functions Some diseases make a person feel sick, others attack places in the body that cannot be felt immediately, i.e. internal organs Symptoms are changes that you can see or feel when you have a disease Coughing can be a symptom of a cold CHARTS/OUHSC Amazing Immune System

Disease Transmission Routes Airborne pathogens – transmitted in air (shown small pox virus) Foodborne pathogens – transmitted through food Bloodborne pathogens – transmitted via blood or body fluids Sexually transmitted diseases are bloodborne pathogens Small pox virus CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System What Are Viruses? Tiny organism, which carries genes that contain instructions for reproducing itself It must invade a living cell in order to reproduce Have you ever been invaded by a virus? (shown Hepatitis B virus) The hepatitis B virus (HBV) causes inflammation of the liver. The virus is recognizable under magnification by the round, infectious “Dane particles” accompanied by tube-shaped, empty viral envelopes. Symptoms of hepatitis B infection include jaundice and a flu-like illness, while chronic infection can lead to serious problems such as cirrhosis and cancer of the liver. CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System What Is HIV and AIDS? HIV – Human Immunodeficiency Virus HIV is the virus that causes AIDS A person with the virus is HIV positive AIDS – Acquired Immune Deficiency Syndrome AIDS is not a virus, but a syndrome HIV+ does NOT mean the person has AIDS The human immunodeficiency virus (HIV) consists of a nucleoside core and the surrounding protein matrix, both enclosed in a lipid envelope. The nucleoid core contains the viral genetic material and the reverse transcriptase enzyme, which are used in viral replication. The transmembrane glycoprotein gp41 and the envelope glycoprotein gp120 are attached to the envelope; these proteins enable HIV to bind and fuse with a target host cell. CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System HIV A retrovirus, meaning that its genetic information is stored on RNA instead of DNA HIV belongs to a unique group of retroviruses, so named because these viruses reverse the usual flow of genetic information Hurts the body’s ability to fight off diseases because it is attracted to cells that have CD4 on their surface In other words, CD4 cells are attacked by the same virus that they are trying to defend against as shown The human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS), principally attacks CD4 T-cells, a vital part of the human immune system. As a result, the body’s ability to resist opportunistic viral, bacterial, fungal, protozoal, and other infection is greatly weakened. Pneumocystis carinii pneumonia is the leading cause of death among people with HIV infection, but the incidence of certain types of cancers such as B-cell lymphomas and Kaposi’s sarcoma is also increased. Neurological complications and dramatic weight loss, or “wasting,” are characteristic of endstage HIV disease (AIDS). HIV can be transmitted sexually; through contact with contaminated blood, tissue, or needles; and from mother to child during birth or breastfeeding. Full-blown symptoms of AIDS may not develop for more than 10 years after infection. CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System HIV Not only can HIV make copies within infected cells, it is also copied when the cell harboring it divides HIV can mutate No medicines exist to date that can completely remove HIV from the body (shown: T lymphocyte invaded with HIV) T lymphocyte invaded with HIV CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System How Is HIV Passed? HIV is not transmitted by casual contact HIV can only be transmitted by close contact with blood and other body fluids, and is transmitted by: Sexual contact, including vaginal, anal, and oral sex Intravenous (IV) drug use Body piercing or tattoos with unsterile equipment Blood transfusions (although very rare today with new blood screening) Mother-to-child, during pregnancy, delivery, or when breast feeding CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System HIV is NOT Passed: Through casual contact like hugging or sharing a hair brush or sharing a meal You will NOT become infected by visiting with or going to school with a person who is HIV positive CHARTS/OUHSC Amazing Immune System

What Happens When The Immune System Fails? HIV is particularly dangerous because its main target is the immune system People infected with HIV can eventually get infections known as opportunistic diseases, or malignancies When white blood cell count drops, the body is defenseless to fight off diseases (Shown: Kaposi’s sarcoma) CHARTS/OUHSC Amazing Immune System

CHARTS/OUHSC Amazing Immune System Global Pandemic CHARTS/OUHSC Amazing Immune System