Presentation is loading. Please wait.

Presentation is loading. Please wait.

compare and contrast active, passive, natural and artificial immunity;

Similar presentations


Presentation on theme: "compare and contrast active, passive, natural and artificial immunity;"— Presentation transcript:

1 compare and contrast active, passive, natural and artificial immunity;
Learning Outcomes compare 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);

2 Immunology Quiz 1. A substance released by helper T cells or by macrophages which have engulfed a pathogen 1a. A named example of the above is 2. Name of the process describing activated immune cells increase in numbers 3. The reason why AIDS sufferers have many opportunistic infections 4. Receptors of immune cells are to specific antigens and are located 5. Phagocytosis is 5a. Agglutination is 6. The part of the macrophage which surrounds the pathogen to be engulfed is

3 Immunology Quiz 1. A substance released by helper T cells or by macrophages which have engulfed a pathogen 1a. A named example of the above is 2. Name of the process describing activated immune cells increase in numbers 3. The reason why AIDS sufferers have many opportunistic infections 4. Receptors of immune cells are to specific antigens and are located 5. Phagocytosis is 5a. Agglutination is 6. The part of the macrophage which surrounds the pathogen to be engulfed is

4 Outline 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)

5 Recap on Phagocytosis Draw the stages. You have 5 minutes
Then you will peer mark another group’s effort Then you can improve your own

6 What happens during inflammation?
Boardworks AS Biology Immunology What happens during inflammation? Teacher notes This 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.

7 Vaccinations

8 Boardworks AS Biology Immunology
Artificial immunity

9 Natural and artificial immunity
Passive Antibodies passed in breast milk Vaccination with antibodies made by another organism eg anti-venom Active Antibodies produced in response to natural infection of microbe Antibodies produced in response to vaccination with damaged microbe Copy the table and fit one of these sentences into each box: Vaccination with antibodies Antibodies produced in response made by another organism to vaccination with eg anti-venom damaged microbe Antibodies produced in Antibodies passed in response to natural infection breast milk of microbe

10 Boardworks 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 Corporation Teacher notes An 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.

11 Vaccinations 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 measles Ring 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

12 Boardworks AS Biology Immunology
Influenza vaccines New 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 / CDC This 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 notes Antigenic 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.

13 Vaccination 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)

14 New Medicines Complete the spider diagram below use p176-7P; p170G
Why we need them New Medicines Sources Methods of Discovery Why is maintenance of biodiversity relevant here?

15 Smoking and Disease describe 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).

16 Cigarette smoke Tar Contains carcinogens Destroys cilia
Carbon Monoxide Nicotine Tar Contains carcinogens Destroys cilia Stimulates goblet cells Increases incidence of infection Causes allergic reactions Smokers Cough – damages linings in airway, smooth muscle thickens, inflammation and wbc mediated destruction of lung linings. Lung Cancer – carcinogens mutate DNA in cells Eg Benzopyrene

17 Diseases Chronic Bronchitis Emphysema COPD Lung Cancer
Use purple book p179 and green book p176-7 to complete the worksheet

18 Nicotine and CO Causes 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 – thrombus CO – carboxyhaemoglobin – raises HR CO – damages artery linings

19 CHD/Stroke Damage of artery inner lining (endothelium)
Phagocytes repair damage by encouraging fatty deposition within walls (Atheroma) Develops into plaque Restricts flow (lumen narrows) and increases chance of thrombosis Coronary arteries (carry blood at high pressure) supply the heart – restricted CA can cause CHD – angina, MI, heart failure. Stroke if occurs in brain.

20 Epidemiology The 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 1978 They did a 20 year prospective study using doctors.

21 Use 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


Download ppt "compare and contrast active, passive, natural and artificial immunity;"

Similar presentations


Ads by Google