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Unit 6 - Circulatory and Immune Systems Circulatory System Key Questions 1. What is the function of the circulatory system? 2. How do necessary molecules enter the circulatory system and cells? 3. What are the parts and functions of the circulatory system? Human Circulatory System Made of 3 key parts: • 1. A system of blood vessels • 2. A heart • 3. Blood Human Circulatory System Types of Blood Vessels 1. Arteries • Typically carry oxygenated blood AWAY from the heart to the rest of the body. • Thick-walled and elastic vessels that expand and contract to accommodate the forceful flow of blood (under great pressure) Human Circulatory System • Pulse = feeling of rhythmic contractions caused by blood flow through arteries. Human Circulatory System • 2. Veins • Return deoxygenated blood back to the heart from all parts of the body • Thin walled vessels that have valves in them to prevent blood from flowing backwards. Human Circulatory System • 3. Capillaries • Tiny blood vessels that are thin enough to allow for diffusion of materials between cells and capillaries Human Circulatory System •4. The Heart A. Function of the heart – to pump the blood Human Heart How the Heart Works (3 min.) https://www.youtube.co m/watch?v=oHMmtqKgs 50 Human Circulatory System • B. Characteristics: • 4 chambered muscle that continually pumps blood throughout the circulatory system. • Made of 2 different sides: one side contains oxygenated blood (left), and one side contains deoxygenated blood (right). • Divided into 2 types of chambers: atria and ventricles. Blood Flow and Gravity! • Experiment: • Hold one hand high in the air. • Hold your other hand down by your side for one minute. • Quickly compare your 2 hands – what happened??? Human Circulatory System • Label Heart Diagram and color the flow of blood through heart Blood Human Circulatory System • 5. Blood A. Functions: Transports things like nutrients, and wastes throughout an organism. Human Circulatory System • b. Made of cells and plasma Human Circulatory System 1. Plasma: a. Made mostly of water (90%) b. Where all materials are dissolved and transported Human Circulatory System • 2. Cells include: red blood cells (RBC’s), white blood cells (WBC’s), and platelets Human Circulatory System Red blood cells - Function • Transport oxygen throughout body FYI – Blood Typing • There are 4 blood types in humans: • A, B, AB, and O • Due to presence or absence of antigens (markers) on surface of RBC’s Human Circulatory System • 4 major blood types: • A, B, AB, O Statistics • http://www.redcrossblood.org/learn-about-blood/bloodtypes Human Circulatory System Platelets – Function: • Cause blood to clot Blood clotting: Platelet Ruptures Releases Enzymes Clotting Begins Human Circulatory System • White blood cells - function • Fight off pathogens Video-2:23 https://www.youtube.co m/watch?v=CRh_dAzXuo U Heart Rate During Exercise • Why does your heart rate increase during exercise??? • To deliver more nutrients to cells and take away wastes When Things Go Wrong: Circulatory System 1. Sickle Cell Anemia • Hereditary disease where red blood cells form an abnormal crescent shape. • Deliver less oxygen to cells than normal rbc’s. • Causes extreme pain • No Cure 2. Hemophilia • Inherited rare bleeding disorder where blood does not clot properly • Decreased amount of or missing clotting factor • No cure. Treatment includes injections of clotting factors 3. Leukemia • Cancer of the blood-forming tissues and lymphatic system. • Usually starts with white blood cells, so the immune system has a lessened ability to fight off infection • Treatment varies depending on type 4. High Blood Pressure • Also called hypertension • When pressure is 140/90 or greater. • Left untreated, can weaken walls of vessels 5. Heart Attack • When the coronary arteries become blocked • Can’t provide nutrients to heart tissue • Leads to tissue death 6. Heart Valve Replacements • Valve Replacements 7. Pacemakers • Small device placed in the chest or abdomen to help control abnormal heart rhythms. • Uses electrical pulses to get the heart to beat at a normal rate 8. Artificial Heart/New Tech • Artificial Heart • Mimics a real human heart • Requires external power system energizes and regulates the pump through a system of compressed air hoses that enter the heart through the chest. • Since the system is cumbersome and open to infection, the use of an artificial heart is meant to be temporary. 9. Stents • Open up blocked vessels Yellow – plaque Red = blood flow The Immune System Key Questions 1. What are pathogens, and how do they affect living things? 2. What are the functions of the immune system, and how does it protect humans? 3. What is active and passive immunity? 4. What are antibodies, and how do they protect us? 5. What are vaccines, and how do they protect us? The Immune System • Part 1: Define Pathogen: • Viruses, bacteria, and other microorganisms that cause disease. Pathogens are found in food, air, water everywhere! ‘Where Germs Really Thrive’ • Question: • Which surface holds more germs, the top of a desk or the toilet seat? ‘Where Germs Really Thrive’ • Answer: The top of a desk has 400 times more bacteria than the average toilet seat! • Info: • Computer keyboards have more germs than door handles. • Other high-germ areas: • Bathroom sinks • Clean laundry (if not washed in hot water) • Phones The Immune System Part 2. Defense systems against pathogens: a. First Line Defenses: • Skin, sweat, mucus, tears, stomach acid, etc. The Immune System b. Second Line Defenses: • Kicks in if pathogen gets past the 1st line • Results in swelling, redness, warmth • Attracts special WBC’s to come and ingest pathogens (non-specific). Phagocytosis Video Clip on server: WBC Chasing Bacteria (30 sec.) The Immune System c. Third Line Defenses: • The Immune System! (Specific) • Put into action when 2nd line did not work! The Immune System • 1. Define Immunity: When the body is able to fight off infection. The Immune System Key terms: a. Define Antigen: • A marker on a cell that can cause an immune response. • Identifies it as being foreign Antigen The Immune System C. Define Antibody: • Specific proteins created by WBC’s that bind to antigens to help destroy pathogens. • Immunity results from the production of antibodies specific to a given antigen. • Video Clip on server: Virus Invades Your Body (3:27) The Immune System • Organisms acquire immunity in following ways: • 1. Active Immunity: When body produces its own antibodies to attack a particular antigen. Occurs in response to either: The Immune System 1. Get infected and recover. * For example: When a person is infected with the chicken pox virus for the 1st time, the body develops antibodies against the organism. The antibodies then remain in the blood and protects the individual from infection by that same organism again. The Immune System 2. Get a Vaccine • A. Define vaccine = injection with a solution that contains dead or weakened pathogens. • Causes body to make antibodies • Organisms in vaccine are too weak to cause an infection. • Booster shots – given to “boost up” levels of antibodies in body. The Immune System 2. Passive Immunity: • Do not make own antibodies • Temporary immunity • Examples: antibiotics, mom to baby Question: 1. Why can we get some illnesses again, like the ‘flu’ if we’ve already had it? • Some pathogens have a high mutation rate. • Our body would see the mutated pathogen as something new and it would have to make new specific antibodies. History and Influenza • 1918 Flu Virus – ‘Spanish Flu’ • Deadliest epidemic in history • Killed 50 million people worldwide • Killed mostly young, strong, healthy adults • Immune systems were over-stimulated • Different from most flu viruses – infects cells deep in the lungs • Lungs filled with fluid http://www.pbs.org/wgbh/nova/body/1918-flu.html (12 min.) The Immune System 2. Allergies a. When the immune system over responds to allergens (things that are not harmful like dust) b. Results in runny nose, itchy eyes, swollen throat The Immune System 3. Transplanted Organs a. Immune system reacts to foreign antigens by producing antibodies to fight off new organ b. Recipient needs to take medication forever to decrease immune response The Immune System 4. HIV and AIDS a. HIV is the virus that can lead to the development of AIDS (Acquired Immune Deficiency Syndrome) b. HIV needs a host cell in order to reproduce and make more copies of itself c. HIV destroys specific white blood cells in the immune system which decreases the ability to fight off infection This is an electron microscope image of HIV. The small, green spheres are the HIV virus on the surface of white blood cells. • d. HIV is transmitted through bodily fluids • Sexually through semen and vaginal secretions • Through contact with blood and breast milk (IV drug use) FYI • When a person is first exposed to HIV, their body produces antibodies against the virus and can keep it under control for years. • During these years, the virus is at constant battle with the immune system. The body tries to get rid of the virus, but is only able to keep it under control. The nature of hiv • After several years, the immune system starts to lose its battle against HIV. • Then, after an average of 10 years of fighting HIV, if the person is not taking HIV treatment, the immune system starts to weaken. This is when full-blown AIDS begins. Symptoms of Advancing HIV • Chronic yeast infections or thrush (yeast infection of the mouth) Fever and/or night sweats Easy bruising Bouts of extreme exhaustion Unexplained body rashes Appearance of purplish lesions on the skin or inside mouth Sudden unexplained weight loss Chronic diarrhea lasting for a month or more Preventing infection • To prevent the spread of HIV, you must prevent contact with an infected person by: • Abstaining from sex • Not using IV drugs • Not using any drugs/alcohol since they impair your judgment • Using latex condoms during any sexual contact • Being in a relationship with only one person and knowing their status Testing • There are several tests that can be used to determine if a person has HIV: • The most common – HIV antibody test (ELISA) • Tests for body’s production of antibodies in response to HIV Treatment • There is no cure for HIV/AIDS. The complexity of HIV has made it difficult to treat. • HIV is a ‘retro-virus’ – it uses RNA as its genetic material instead of DNA • It has a high mutation rate (changes in genetic material) treatment • Current treatment: • Using antiretroviral drugs to keep the amount of HIV in the body at a low level. • These drugs need to be taken every day for the rest of the person’s life.