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);

•

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...................

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...................

• 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)

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

What happens during inflammation?

Vaccinations

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Artificial immunity

Natural and artificial immunity

Natural Artificial

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

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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.

They may contain isolated antigens, such as cell surface proteins, from the pathogen.

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

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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.

The government works with other organizations to identify current strains of influenza. An effective vaccine is developed each year.

Antigenic variation makes it hard to immunize a patient against the influenza virus for life with just a single vaccine.

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• 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)

New Medicines• Complete the spider diagram below use p176-7P; p170G

New Medicines

Why we need them

Sources

Methods of Discovery

Why is maintenance of biodiversity relevant here?

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).

•

Cigarette smoke

• 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

TarCarbon MonoxideNicotine

Diseases

• Chronic Bronchitis• Emphysema• COPD• Lung Cancer

• Use purple book p179 and green book p176-7 to complete the worksheet

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

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.

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 34 000 doctors.

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