Communicable Diseases A disease cause by and agent
Communicable Diseases A disease cause by and agent that can be passed from one living thing to another.
Contamination – how germs are passes (5: 46) https: //www. youtube. com/watch? v=k 1 j 8 bh 8_O_Q 6 People are exposed to a cold virus, predict how many will get the germs on them? The Safe Sneeze by Mythbusters (4: 29) https: //www. youtube. com/watch? v=3 vw 0 h. Is 2 LEg How far do you think a sneeze will travel? Which protects others better when you sneeze? � Hand � Elbow � Handkerchief
Lesson 1 Understanding Communicable Diseases What Causes infectious Disease �Pathogen – Any agent that causes disease – �Bacteria �Virus �Fungi �Protozoa larger and more complex than bacteria (example: Malaria) �Rickettsias resemble bacteria, but enter through insect bites. (example: typhus) These are the causes of infectious disease
How are infections spread Direct contact � Touching – puncture wounds (ex. Rusty nail) � Biting – (ex. Animal bites) � Kissing � Sexual contact or childbirth � (ex: infection from mom to child through placenta Indirect Contact – Contaminated objects � Through the Air (sneezing) � Contact with a contaminated object (doorknobs) � Person to Person (shaking hands, kissing) Vectors � Animals (deer – lyme disease, infected dog (ringworm, rabies) Contaminated Food and Water � Food and Water (eating contaminated food or water)
Video Clips on Colds and Flu – symptoms and how to protect (4: 53) https: //www. youtube. com/watch? v=4 uz. Nn. Km 41 W 8 Flu vs. Cold (4: 53) https: //www. youtube. com/watch? v=Aae. UX 5 l. Fx-s How the Flu attacks your body (3: 38) https: //www. youtube. com/watch? v=Rpj 0 em. EGSh. Q
Lesson 3 Fighting Communicable Diseases Physical and Chemical Diseases Make up your body’s 1 st line of defense against pathogens. �Physical barriers. �Skin �Cilia – small hairs in respiratory system. Sweep mucus and pathogens to the throat to be swallowed or coughed out. �Chemical methods – destroy those invaders �chemicals found in sweat �Enzymes found in tears & saliva �Gastric juice in stomach
The Immune System network of cells, tissues, organs and chemicals that fights off pathogens. Inflammatory response � reaction to tissue damage caused by injury or infection. � Prevents further injury and stops pathogens 1. In response, blood vessels expand, more blood to the area 2. Fluid and cells from the bloodstream cause swelling and pain. Pressure on the nerve endings 3. Phagocytes, white blood cells attack invading pathogens. 1. Pus, mass of dead white blood cells and damaged tissue may build up at the site of inflammation to fight bacteria. 4. With pathogens killed and body repairs tissue � Bacterial Disease – such as strep throat, sinus infections can be treated with antibiotics � Viral Diseases – such as the flu, chickenpox, or mononucleosis, do not respond to antibiotics.
Fighting Disease �Bacteria, viruses, and other agents of disease are everywhere around us: �Air we breath �Surfaces we touch �On our skin Even if it enters your body, it cannot make you sick unless it survives, multiplies and causes damage to your system. Most of the time, pathogens are quickly destroyed or swept away before they have a chance to multiply
Infection & Disease If pathogens do enter your system and begin to spread and reproduce, then you are infected. �Body can still defend against them, destroy or make them harmless (chicken pox, virus stays in your body Disease – harmful change in your body’s normal activities �Feel sick �Damage to your cells and tissues Signs & Symptoms – effects of a disease �Something a person can see (sneezing, coughing, pale/flush skin) �Feeling of pain or discomfort (sore throat, tiredness, nausea)
Defenses against infection Skin Chemical warfare on germs �Sweat & oils contain acids that kill bacteria �Enzymes in tears and saliva Mucous Membranes �Tissues lining the openings into your body (mouth and nose) Stomach Acids �Some pathogens might enter your system when you touch your fingers to your lips, breathe through your mouth or bite your nails. �Most are destroyed in your stomach Helpful Microorganisms � bacteria live on the skin and in your mouth. Take up space and leave not room for other pathogens.
Inflammation (swollen, red, painful) �Phagocytes (found in white blood cells) attack, eat and destroy any microorganisms. Immune System �Destroy invaders in time to prevent diseases �bone marrow – grows white blood cells lymphocytes �Thymus gland – incubates some lymphocytes and changes them into T-cells (they recognize enemies) or other lymphocytes become B Celle (they make antibodies) Lymphocytes travel in body fluids during infection they are drawn to lymph nodes Our Immune System – Our Body’s 1 st Line of Defense https: //www. youtube. com/watch? v=3 UAo 6 V 6 Ego. U
�T & B cells work together �Recognize �Fire antibodies �Capture �Memorize
Immunity �Innate Immunity �Some people seem to inherit resistance to certain human diseases �Active Immunity �Once your body has launched an all-out war against a specific invader, it remains armed and ready to fight that same invader much more quickly and effectively. Passive immunity you have received antibodies from another person or sometimes and animal that have made you resistant to disease or infection How do immunizations work?
Common Viral Diseases �Common cold �Influenza �Chickenpox �Mononucleosis �Hepatitis �Measles Cold or Flu, what is the difference? https: //www. youtube. com/watch? v=Aae. UX 5 l. Fx-s
Common Bacterial Diseases �Strep throat (sore throat, can cause permanent heart and kidney damage) �Tuberculosis (attacks lungs and cause fluid to build up there) �High fever, weakness, loss of appetite) Sinus Infections cold, flu, or allergy that leads to heavy mucus production can lead to a bacterial infection in our sinuses)
Where Are The Most Bacteria-Filled Places In Your Life? https: //www. youtube. com/watch? v=NYgv. Ctrdu 2 U 25 Bacteria Facts That Might Make You Feel Dirty https: //www. youtube. com/watch? v=Lg-1 Vv 4 -58 M Resistance (1: 11) Bacteria’s becoming Resistant to antibiotics, why would we be in danger? https: //www. netflix. com/watch/80028086? trkid=14170056&tctx=3%2 C 2%2 Cf 57839 be-37 b 5 -4 d 40 -a 3358 ce 1 ef 1 f 4628 -14810579
THREATS TO HUMAN HEALTH PRESENTED BY VIRUSES � When it was discovered that bacteria could cause disease, there were many illnesses for which bacterial agents could not be found. These included serious diseases such as smallpox, polio, rabies and influenza, as well as less serious maladies such as the common cold. These diseases, and many more, are caused by viruses. � Viruses are infectious agents which are between 20 and 100 times smaller than bacteria. They are too small to be seen through a normal microscope and can be visualized only by an electron microscope. Viruses consist of strands of genetic material (RNA or DNA) surrounded by a coating of protein (called a capsid). Viruses are not considered to be living organisms because they cannot reproduce outside of a living cell.
How they infect � Viruses multiply by inserting their genetic information into a cell and harnessing the cell machinery to replicate the viral genetic material and make new capsids. The new viruses are then transmitted to other cells, either through the cell wall or when the cells burst and die. Viruses are parasites on a cellular level. � New strains of disease-causing viruses are a constant threat because viruses mutate easily. For example, each year a new influenza virus causes illness in millions of people. As a result, and because most drugs cannot disable a virus without harming healthy tissue, it is difficult to develop drug therapies to cure viral infections. Flu: How a virus invades your body https: //www. youtube. com/watch? v=Rpj 0 em. EGSh. Q
Ebola � Viruses can be transmitted from one animal species to another. They affect each species differently and one species can harbor viruses deadly to another without any ill effect. For example, most Ebola viruses and the Hanta virus, do not cause disease in their host animals, but they are deadly to man. The Ebola-Reston virus, on the other hand, is deadly to monkeys but does not cause illness in humans. � Viral illnesses can be spread in a number of ways. Some, such as AIDS and Ebola, can only be spread through exchanges of blood or other bodily fluids. Others, such as influenza and the common cold, are airborne and enter through the respiratory tract. The Hanta virus is spread by breathing dried rodent feces which become airborne. Ebola: The Deadliest Outbreak Explained https: //www. youtube. com/watch? v=JNi. H 18 JNmq. A
Quarantine �Quarantine deprives people of their liberty not because they have committed any crime, but due to their exposure to a dangerous communicable disease. The power of the state to impose quarantines has been recognized for many hundreds of years. In the United States, there has never, to our knowledge, been an instance when the state was granted the power to kill people exposed to disease. This is clearly a gross deprivation of due process. The only way that it could be justified is if it were a certainty that the entire country, or large portions of it, would be wiped out unless the action was taken. The film explores this dilemma.
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