Transcript Diseases
Diseases Unit 5 By Definition o Infectious disease o Caused by an agent that has invaded the body. o Communicable disease o Can be spread or passed o Non-infectious disease o Occurring from within the body, heredity, lifestyle o Non-communicable disease o Cannot be passed on o Pathogen o Any agent that causes disease Types of Pathogens • • • • • • Bacteria (including toxins) Rickettsia Viruses Fungi Protozoans Parasites Bacteria • A single-celled microbe or organism • One of the widest spread of all living things • Three Basic Types (Identified by Shape) – Bacilli = rod shaped – Cocci = spherical shaped. Long chains are streptococcus and clusters(grapes) are staphylococcus. – Spirillia = twisted or spiral shaped Bacteria continued… o Resident Bacteria – live on the human body to help protect you from infection o Mouth, skin, intestines o More than 300 in your mouth o Some bacteria give off poisons while others enter and damage cells. o Examples: Tuberculosis, tetanus, sinus infections Toxins • Bacteria that produces poisons – Food Poisoning: effect depends on type and amount ingested leads to upset stomach, loss of respiration, and death. – Tetanus: a toxin found in the ground that enters through a wound or injury. Bacteria cells split at such a rate that one cell not attacked in 15 ½ hours turns into 4.3 billion Rickettsia • Pathogens that grow inside living cells • Cause typhus, Rocky Mountain Spotted Fever Viruses • Smallest pathogen known to man • Made of genetic material and a protein coat • Takes over the living cell by release of nucleic acid, force cells to make new viruses • Spread rapidly and attack specific cells(Rabies=brain cells; HIV=T cells) • Examples: colds, mumps, flu, measles, HIV, AIDS, and severe acute respiratory disease(SARS) Fungi • Single or multi-celled organisms that absorbs and uses nutrients of living or dead organisms. • Feeds off of plant, animal, human tissue • Live on skin, in lungs • Cause ringworm, jock itch, thrush, athlete’s foot Protozoans • Single-celled organisms that produce toxins that cause a disease. • Larger and more complex internally than bacteria • Cause: Malaria, African Sleeping Sickness, and Amebic Dysentery Parasites • Animal parasites get their energy and nutrients by feeding on other living things – Helminth – Tapeworms – Flatworms – Pinworms – Hookworms – Flukes – Head lice Found in undercooked meat. Infect digestive tract, muscle tissue and blood. Poor hygiene. Immunity • Active Immunity: when you have had the disease, you build antibodies. • Passive Immunity: Is passed from mother to baby during development or from transplants • Vaccines: Lead to active immunity by injecting a weakened or dead form of the disease. • Antibiotic Resistance: a condition in which bacteria can no longer be killed by a particular antibiotic. Spreading Disease • Close contact – Sneeze, cough • Direct contact – touching • Contact with a vector(animal, insect) – Mosquito, dog • Contact with a fomite(object) – Food, water D, D, D, Defense • Major Defenses – Mechanical: dead cells, skins, mucous membranes – Chemical: resident bacteria, tears, gastric juices – Biological: the release of chemicals by the immune system. • White blood cells called neutrophils eat bacteria • Monocytes from the bone marrow eat bacteria also. More Defense • Affected body cells release INTERFERON, a protective protein. • Fever is formed when the body can’t rid itself of internal heat. Fever weakens and kills some pathogens. • Some bacteria carry pyrogens(poison) that cause fever. Common Bacterial Diseases • Meningitis – Inflammation of the membranes covering the brain and spinal chord. – May also be caused by viruses or sometimes by fungi or parasites – Spread my contact with saliva or mucus from infected person – Severe headache, fever, stiff neck sensitive to light, nausea – Can be treated by antibiotics if bacterial and caught early. • Tetanus – Lockjaw, affects the nervous system and causes painful, uncontrolled muscle spasms – Clostridium tetani, spores found in soil, enters body through wounds/cuts. – Treated with antibiotics, tetanus shot(every 10yrs) Bacterial Diseases • Salmonellosis – Infection of the digestive system from eating contaminated foods. – Headache, cramps, diarrhea, nausea, vomiting – OTC meds for symptoms, sometimes antibiotics – Cook foods thoroughly, wash hands • Strep Throat – Sore throat, fever, yellow or white specks on tonsils – Spread through contact with infected person – Take antibiotics Bacterial Diseases • Sinus Infections – Headache, tenderness of the sinuses, thick and greenish mucus, feeling of pressure in the head – Spread through contact with infected persons, allergens such as cigarette smoke or air pollutants – Treat with antibiotics • Influenza Virus Viral Infections – – – – Flu Headache, sore muscles, sore throat, fever, fatigue, cough Spread by contact with infected person Vaccinations; however, new ones developed each season b/c of new strains developed – Get plenty of rest and fluids • Cold – Scratchy, sore throat; sneezing and runny nose; cough – Spread by contact with infected person – Wash hands, avoid infected people, get rest and fluids, treat symptoms • Mumps – Pain and swelling of glands in throat, fever, headache – Spread by contact with infected airborne droplets and personal contact – Vaccinations – Rest and plenty of fluids Viral Infections • Measles – Rash covering body, fatigue, runny nose, cough, slight fever, small white dots in mouth – Spread by contact with infected person – Vaccination • Mononucleosis – Fever, swollen lymph nodes, sore throat, weakness – Spread by contact with infected person – Avoid drinking or eating after others Viral Infections • Hepatitis – Inflammation of the liver, jaundice, fever, darkening of the urine – Spread by contact with bodily fluids of infected person and by eating/drinking infected food or water – Types A, B, C • A- vaccine, washing hands regularly • B- vaccine to prevent, but cannot once infected • B & C- life threatening, no cure Fungal Infections • Athlete’s foot • Jock itch • Ringworm – Skin becomes itchy and red and lesions may appear. – Keep clothing dry and practice good hygiene – OTC meds will kill the fungus Protozoan Infections • Often found in water and soil • About 20,000 kinds of protozoa, but only small number cause disease • Amebic dysentery: inflammation of intestine caused by an ameba causing nausea, diarrhea. • Malaria – – – – – Plasmodium Passed by mosquitoes Approx one million people die each year Fever, chills, headache, fatigue, nausea Can be prevented and treated with antimalarial drugs. Parasitic Infections • Inside body – – – – Hookworms Flukes Pinworms Tapeworms • On the body – – – – Lice Leeches Ticks Fleas Lifestyle Diseases • Lifestyle Disease – Diseases that are caused partly by unhealthy behaviors and partly by other factors. • Controllable Risk Factors – – – – Diet and body weight Daily levels of physical activity Level of sun exposure Smoking and alcohol abuse • Uncontrollable Risk Factors – – – – Age Gender Ethnicity Heredity Cardiovascular Disease • A disease or disorder that results from progressive damage to the heart and blood vessels • The leading cause of death in the US – Stroke – High Blood Pressure – Heart Attack – Atherosclerosis Stroke • Sudden attacks of weakness or paralysis that occur when blood flow to an area of the brain is interrupted. • Blood clot lodges in artery and cells begin to die due to loss of circulation or hole forms in a blood vessel and blood leaks into the brain • 160,000 deaths each year • Warning Signs – – – – Numbness or weakness in face, arm or leg Trouble seeing in one or both eyes Sudden dizziness or loss of coordination Sudden, severe headache with no known cause High Blood Pressure • Hypertension, the silent killer • Blood pressure is the force that blood exerts against the inside walls of a blood vessel. Too high=extra strain on the walls and the heart. • Will cause the heart to weaken or fail Heart Attack • The damage and loss of function of an area of the heart muscle. • About 1/3 are fatal • Blood clot gets stuck in one of the coronary arteries and stops blood flow to the heart. Heart cells die from lack of oxygen. • Warning Signs – Pressure, squeezing, or pain in center of chest – Pain spreading to shoulders, neck, arms – Chest discomfort with lightheadedness, fainting, sweating, nausea, shortness of breath Atherosclerosis • The disease characterized by the buildup of fatty materials on the inside walls of the arteries. • Reduces or stops blood flow to parts of the body • Deposits break free and release clots into the bloodstream – May result in heart attack or stroke Detection • Check blood pressure – Normal falls between 80/50 and 130/85 – 140/90 is considered high • Electrocardiogram – EKG, measures electrical activity of heart to detect damage or irregular heart beat • Ultrasound • Angiography – Inject dye into coronary arteries to look for blockages Treatment and Prevention • Treatment – – – – – – Diet and exercise Medicine Surgery Angioplasty Pacemakers Transplants • Prevention – Cut down on fat and salt intake – Maintain healthy weight – Don’t smoke – Exercise – Check BP and cholesterol – Relax