Terms To know Infectious Disease disease caused by

Terms To know Infectious Disease : disease caused by a microscopic germs that can pass from one thing to another. Some cannot pass to new individuals. Communicable Disease : an infectious disease that is passed from one person to another. Microorganisms : a living that can be seen only with a microscope (Ex: bacteria, fungi, protists). Pathogens : any agent that causes diseases. 2 most common pathogens Other Pathogens 1. Bacteria - fungi 2. Viruses - protists - parasitic worms

Bacteria • Unicellular microorganism that can cause disease; majority are harmless, but some are pathogenic (1%) • Can kill bacteria with antibiotics • Binary Fission- reproduction of bacteria by splitting of the body into 2 new bodies. Types of Bacteria (common) • • • Strep throat Food/water poisoning Urinary-tract infection Tuberculosis Staph Infection- MRSA (antibiotic resistant) • Yersinia pestis

Virus • A microscopic disease causing particle consisting of genetic material and a protein coat • Attacks and kills living cells to make new viruses • NO CURE Types of viruses (common) • mononucleosis. Polio • hepatitis. Measles • influenza. Tetanus • cold sores (herpes simplex type 1) • Chicken pox. Small Pox

Other pathogens q. Fungi (mushrooms, mold, mildew) • athlete’s foot, ringworm, yeast infection q. Protists (single or multi-celled organism) • Malaria, giardia infection • Parasitic Worms (multicellular organism) • tapeworm (water/meat), flatworm (water), hookworm (feces/soil), roundworm (meat)

How are Infectious Diseases Spread? 1. Through the air Ex: chicken pox, flu, tuberculosis 2. Contact with Contaminated Objects Ex: poison ivy 3. Person to person Ex: HIV, STDs, monucleousis 4. Food and Water Ex: salmonella, E-coli 5. Animal Spreading Diseases Ex: malaria, rabies, Lyme disease

External and Internal Defense Innate Immunity- non specific defense a. Skin Epidermis: physical barrier b. Chemical Warfare on Germs: tears, saliva, ear wax, fever, inflammatory response c. Mucus Membranes: line body cavities of respiratory, urinary, and digestive tract d. Stomach Acids e. Helpful Microorganisms f. Phagocyte Cells (patrol the circulatory system “find and eat” unnatural cells)

Your Immunity Acquired Immunity- antigen specific defense • Active immunity- natural or artificially developed immunity. • Passive immunity- antibodies acquired from mother to child during pregnancy or injected. 1. Immune system – protects body from disease 2. Vaccination – injection of a small amount of a pathogen that will provide protection against an infections disease (live, killed, toxoid, 2 nd generation) 3. Antibiotics – drugs that kill or limit the growth of bacterial infections not viruses.

How the Immune System Works 1. 2. 3. 4. 5. 6. 7. 8. Pathogens – disease causing agent gets past external innate defense mechanisms. Macrophage – phagocyte that engulfs pathogen using cytoplasmic extensions and ingest and display it Helper T cells – drive the immune system response; activation of B Cells and killer T Cells Killer T cells – kills or neutralizes infected cells. B cells – bind to antigen divides & clones. Produce antibodies and remembers the antigen. Antibodies – protein that marks antigen for destruction & neutralizes it by blocking binding sites Suppressors T cells – turns off immune system when the infection is cleared. Regulates self-tolerance (prevents body from not attacking own cells) Memory T cells – remembers the antigen & immediately attacks (secondary immune response)