Presentation on theme: "compare and contrast active, passive, natural and artificial immunity;"— Presentation transcript:
1compare and contrast active, passive, natural and artificial immunity; Learning Outcomescompare and contrast active, passive, natural and artificial immunity;(m) explain how vaccination can control disease (HSW6a, 7c);(n) discuss the responses of governments and other organisations to the threat of new strains of influenza each year (HSW7b, 7c);(o) outline possible new sources of medicines, with reference to microorganisms and plants and the need to maintain biodiversity (HSW 6a, 6b, 7b);
2Immunology Quiz1. A substance released by helper T cells or by macrophages which have engulfed a pathogen1a. A named example of the above is2. Name of the process describing activated immune cells increase in numbers3. The reason why AIDS sufferers have many opportunistic infections4. Receptors of immune cells are to specific antigens and are located5. Phagocytosis is5a. Agglutination is6. The part of the macrophage which surrounds the pathogen to be engulfed is
3Immunology Quiz1. A substance released by helper T cells or by macrophages which have engulfed a pathogen1a. A named example of the above is2. Name of the process describing activated immune cells increase in numbers3. The reason why AIDS sufferers have many opportunistic infections4. Receptors of immune cells are to specific antigens and are located5. Phagocytosis is5a. Agglutination is6. The part of the macrophage which surrounds the pathogen to be engulfed is
4Outline two ways that antibodies reduce the threat from pathogens (4) (Jan 2013) Neutralisation (1) Prevent pathogen binding to receptor and infecting cells/binding toxins (1)Agglutination (1) Clumps together many pathogens so cannot enter cell/more likely to be engulfed by phagocyte (1)
5Recap on Phagocytosis Draw the stages. You have 5 minutes Then you will peer mark another group’s effortThen you can improve your own
6What happens during inflammation? Boardworks AS BiologyImmunologyWhat happens during inflammation?Teacher notesThis animation shows the process of acute inflammation. If acute inflammation persists (for example, if a foreign body remains embedded in the skin) or occurs repeatedly, it can lead to chronic inflammation. This involves different cells of the immune system and leads to simultaneous tissue damage and attempts at tissue healing.Chronic inflammation can also occur due to a range of infectious and autoimmune diseases, such as tuberculosis, inflammatory bowel disease (Crohn’s disease and ulcerative colitis) and rheumatoid arthritis, as well as exposure to chemical substances such as silica.
8Boardworks AS Biology Immunology Artificial immunity
9Natural and artificial immunity PassiveAntibodies passed in breast milkVaccination with antibodies made by another organismeg anti-venomActiveAntibodies produced in response to natural infection of microbeAntibodies produced in response to vaccination with damaged microbeCopy the table and fit one of these sentences into each box:Vaccination with antibodies Antibodies produced in responsemade by another organism to vaccination witheg anti-venom damaged microbeAntibodies produced in Antibodies passed inresponse to natural infection breast milkof microbe
10Boardworks AS Biology Immunology What is vaccination?Vaccines stimulate the production of antibodies and memory cells against the target pathogen without causing illness.Why don’t vaccines cause illness?They may contain an inactivated form of the pathogen, killed by heat treatment (which leaves the immune-stimulating antigens intact).They may contain an attenuated (less virulent) form of the pathogen.Photo credit: Jupiterimages CorporationTeacher notesAn attenuated vaccine contains a less virulent form of the pathogen, obtained through artificial selection or genetic modifications.In order to protect a whole community against an infectious disease, at least 80% of the population need to be immunized. This keeps the level of transmission low, protecting those who cannot be immunized. This group protection is called herd immunity. The percentage needed to maintain herd immunity varies between different diseases; for example, the herd immunity threshold for measles is 83–94%.They may contain isolated antigens, such as cell surface proteins, from the pathogen.
11Vaccinations against diseases Herd Immunity – Once enough of population immunised, disease can no longer spread.Estimated that 95 % of the population need to be immunised to prevent the spread of measlesRing Vaccination – New case of a disease reported. Vaccinating people in the immediate vicinity of infection can control the spread of the disease.Often used in livestock diseases - eg foot and mouth
12Boardworks AS Biology Immunology Influenza vaccinesNew strains of the influenza virus are constantly emerging. This is because antigens displayed on the virus change due to mutation. This causes antigenic variation.Antigenic variation makes it hard to immunize a patient against the influenza virus for life with just a single vaccine.The government works with other organizations to identify current strains of influenza. An effective vaccine is developed each year.Photo credit: Cynthia Goldsmith / CDCThis negative-stained transmission electron micrograph (TEM) depicts the ultrastructural details of an influenza virus particle, or “virion”. A member of the taxonomic family Orthomyxoviridae, the influenza virus is a single-stranded RNA organism.Teacher notesAntigenic variation can occur in other pathogens. Antigenic drift leads to a minor change in antigens and is caused by genetic mutation. Antigenic shift leads to major changes in antigens and is caused by genetic recombination between individual pathogens.There has also been little success in developing an effective vaccine against malaria. The malarial parasite frequently undergoes antigenic variation, making it hard to target. It also spends a lot of time within the host’s liver and blood cells, effectively hiding from the host’s immune system.
13Vaccination past question In an attempt to reduce outbreaks of influenza, the government encourages vaccination of at risk groups such as the elderly and young children,Give two more examples of at risk groups and explain why they are at risk. (4)AIDS/HIV sufferers/transplant patients (1) Weak/Suppressed immune system, more likely to become infected (1)Pregnant women (1) Allows protection of foetus (1)Health Workers (1) High level of exposure to disease (1)
14New Medicines Complete the spider diagram below use p176-7P; p170G Why we need themNew MedicinesSourcesMethods of DiscoveryWhy is maintenance of biodiversityrelevant here?
15Smoking and Diseasedescribe the effects of smoking on the mammalian gas exchange system, with reference to the symptoms of chronic bronchitis, emphysema (chronic obstructive pulmonary disease) and lung cancer;(q) describe the effects of nicotine and carbon monoxide in tobacco smoke on the cardiovascular system with reference to the course of events that lead to atherosclerosis, coronary heart disease and stroke;(r) evaluate the epidemiological and experimental evidence linking cigarette smoking to disease and early death (HSW3, 6a, 7a, 7b, 7c).
16Cigarette smoke Tar Contains carcinogens Destroys cilia Carbon MonoxideNicotineTarContains carcinogensDestroys ciliaStimulates goblet cellsIncreases incidence of infectionCauses allergic reactionsSmokers Cough – damages linings in airway, smooth muscle thickens, inflammation and wbc mediated destruction of lung linings.Lung Cancer – carcinogens mutate DNA in cellsEg Benzopyrene
17Diseases Chronic Bronchitis Emphysema COPD Lung Cancer Use purple book p179 and green book p176-7 to complete the worksheet
18Nicotine and COCauses adrenaline release – speeds up heart, breathing rate and causes constriction of arterioles (leads to inc in BP and possible loss of extremities)Causes platelets to become sticky – thrombusCO – carboxyhaemoglobin – raises HRCO – damages artery linings
19CHD/Stroke Damage of artery inner lining (endothelium) Phagocytes repair damage by encouraging fatty deposition within walls (Atheroma)Develops into plaqueRestricts flow (lumen narrows) and increases chance of thrombosisCoronary arteries (carry blood at high pressure) supply the heart – restricted CA can cause CHD – angina, MI, heart failure.Stroke if occurs in brain.
20EpidemiologyThe study of distribution of a disease in populations and the factors that influence its spread.The link between smoking and lung cancer was established by Doll and Peto in 1978They did a 20 year prospective study using doctors.
21Use green book p178-9 Handouts provided Past paper question: p16, Q5a (Jun 2012)Describe the trends in the data (4)Mark scheme p23, ans 5a