1. Immunology revision cards
Catherine Haworth

2. Instructions for making revision cards
Print off slides 3–11, back to back, onto card.
Cut out each card.
On the front of each card is either a question or a requirement from the specification.
On the back is the answer to the question or what is required by the specification.

3. Cause and transmission of malaria
Define health.
Define disease and
give an example.
Define parasite and
give an example.
Define pathogen and
give an example.
Cause and transmission of malaria
Cause and transmission of AIDS and HIV
Cause and transmission of Mycobacterium tuberculosis
Describe treatment and prevalence of malaria.
Describe treatment and prevalence of AIDS and HIV.

4. – an organism that causes disease. Pathogens are a type of parasite.
Anything that impairs the normal functioning of the body and causes physical, mental or social symptoms, e.g. malaria caused by Plasmodium, which is carried by female Anopheles mosquito
An organism that lives in close association with its host and causes it harm. Parasites harm their host by taking nutrition from them. Not all parasites are pathogens, e.g.
– physical, mental and social well being and not merely the absence of disease or infirmity (WHO)
– an organism that causes disease. Pathogens are a type of parasite.
To cause infection a pathogen must be able to:
be transmitted from host to host
enter the host tissue
reproduce
cause damage to the host tissue
e.g. Plasmodium falciparum, Mycobacterium tuberculosis
Malaria is caused by one of four species of Plasmodium (falciparum, vivax, ovale, malariae).
It is transmitted via a vector (female Anopheles mosquito).
AIDs (acquired immune deficiency syndrome) is caused by the destruction of T helper cells by the virus HIV (human immunodeficiency virus).
Transmission is by contact with blood, e.g. blood transfusion, sexual intercourse, placenta, via breast milk, sharing contaminated needles.
Malaria is widespread in countries where mosquitoes are prevalent.
Prevention is possible via the use of nets to prevent mosquitoes biting.
Mosquito populations can be reduced by spraying insecticides.
Drugs can reduce the spread of Plasmodium in body.
Vaccinations are not used due to antigens being hidden, and the short life cycle of malaria outside of cells.
Tuberculosis is caused by a bacterium, Mycobacterium tuberculosis.
It is transmitted via droplet infection through the air, through sneezing, coughing and spitting.
AIDs is prevalent where there is sexual promiscuity.
Prevention is possible by:
using a barrier e.g. condoms during sexual intercourse
screening blood products
needle exchange schemes
health education about safer sex

5. Describe the treatment and prevalence of Mycobacterium tuberculosis.
Define immune response.
Define antibody.
Define antigen.
Describe the action of phagocytes and give examples.
Describe the primary defences against pathogens and parasites.
Primary lines of defence: mechanisms to prevent the pathogen entering the body
Relate antibody structure and function.
Describe the processes of neutralisation and agglutination.
Describe the structure and function of helper T cells

6. Specific shape that is complementary to that particular antigen
Large protein molecules that can recognise and neutralise antigens. Known as immunoglobulin e.g. IgG, IgA.
Specific shape that is complementary to that particular antigen
Tuberculosis is widespread in overcrowded areas.
It can be prevented by
BCG vaccination.
A long course of antibiotics is required to treat infections.
The way in which white blood cells react when pathogens enter the body. A response to an antigen which involves the activation of lymphocytes.
Two types of non-specific white blood cells are produced in the bone marrow. They engulf and digest foreign particles throughout the body. Neutrophils are short-lived and tend to die after engulfing bacteria. Multi-lobed nucleus. Numbers rise as a result of infection.
Macrophages are long lived – they survive after engulfing bacteria. Settle in lymph nodes, spleen and kidney. Important in the specific immune response.
Mode of action of phagocytes Host tissue is invaded by pathogens. Damaged cells release histamines which attracts phagocytes. Phagocyte engulfs the bacterium by phagocytosis.
The skin – the outer layer of the epidermis consists of dead keratinised cells – keratinocytes – which act as a physical barrier to pathogens.
Commensal flora – harmless bacteria that live on the skin surface and compete with pathogenic bacteria.
Mucous membranes – found in the gut, genital areas, anus, ears nose and respiratory passages. An epithelial layer of cells containing mucus-producing goblet cells. The sticky mucus lines the passages and traps pathogens. The respiratory tract contains ciliated cells which waft mucus to the top of the trachea; it is swallowed and passes into the stomach (pH 2).
Eyes produce tears which contain antibodies and lysosymes. Ears produce wax, which traps pathogens and lysosymes.
Vagina – secretions contain lactic acid – low pH.
A substance that is recognised as foreign by the immune system.
Antigens include proteins, polysaccharides and glycoprotein molecules.
They stimulate an immune response.
Usually have a specific shape.
Can be on the surface of bacteria or virus.
Can be on the cell surface of foreign tissue such as organ transplants and transfused blood cells.
Can be free molecules such as toxins released by microbes.
Each type of pathogen has its own unique antigens; these are genetically determined.
Binding site
Agglutination – forming antibody–antigen complexes the pathogens are held together in large clumps. Macrophages and neutrophils can more easily engulf pathogens that are immobilised by agglutination
Neutralisation – antigens which are toxins are rendered harmless if they are blocked by being bound to an antibody
Migrate to the Thymus gland to mature.
T helper cells release cytokinins which stimulate B cells to develop, and stimulate phagocytosis by phagocytes.

7. Describe the structure and function of T killer cells.
Describe the structure and function of T memory cells.
Describe the structure and function of B memory cells.
Describe the primary immune response.
Describe the secondary immune response.
Describe the structure and function of B plasma cells.
Why is immunity lost when an individual leaves an area where the disease is prevalent?
Compare and contrast the primary and secondary immune responses.
What are the four types of immunity?
Give examples for each type.

8. Mature in the Bone marrow.
T killer cells – attack and kill infected cells; secrete chemicals to destroy infected cells and pathogens
Mature in the Bone marrow.
Remain in the body for years and act as an immunological memory.
Migrate to the Thymus gland to mature.
Remain in the body for years and act as an immunological memory.
The primary immune response – when a pathogen enters the body, it takes time to produce cloned plasma B cells, which secrete antibodies complementary to the pathogens antigen. The antibody level in the blood will rise. However, the delay can result in the person suffering from the disease. Once the pathogen has been eliminated, the blood antibody level falls. Specific memory B cells will remain.
The secondary immune response – if the same pathogen (with the same antigens) reinvades the body, the specific memory B cells will be activated and clone rapidly to produce more antibodies faster.
B plasma cells secrete antibodies. They contain many mitochondria and RER because they need to make lots of protein antibodies.
Natural
Artificial
Passive
Maternal antibodies cross the placenta and from breast milk.
Administered antibodies used e.g. to treat rabies.
Active
Natural exposure to antigen. Body makes own antibodies
Immunisation with a vaccination. Body makes antibodies in response to harmless antigen.
Primary response: only one specific B cell not yet differentiated.
Secondary response: more specific memory cells (already differentiated).
Primary response: takes time for B cells to be activated, clone and differentiate. Get symptoms.
Secondary response: quicker since memory cell already differentiated, more memory cells to start with so lots of antibodies can be made more quickly. No symptoms.
When the individual leaves:
no further exposure to antigen
no further memory cells made
any memory cells in body will die
not possible to launch a secondary response
lose immunity (i.e. will show symptoms on re-infection)

9. Explain why new vaccines are needed for influenza each year.
How does vaccination control disease?
Describe potential new sources for medicines (inc. biodiversity)
What is complement?
Describe the malaria (Plasmodium) life cycle.
Examples of cell signalling
Examples of ways to make vaccinations
Describe cytokine signalling.
Define cell signalling.
You must die!

10. Medicines may come from rare plants and animals.
If biodiversity is not preserved then sources of medicines will be reduced.
Examples of medicines from nature:
Aspirin from willow
Digitoxin from foxglove
Laxative from the plant Senna alexandrina
Morphine from poppy Papaver somniferum
Influenza is a virus. Antigens on the surface of the virus show antigenic drift (i.e. change shape regularly). Each time the antigen changes shape, the memory cell produced by the vaccine will no longer produce complementary antibodies.
New vaccines need to be made so that new memory cells will be made for each strain of the virus.
Vaccination stimulates an immune response by providing antigens that are not pathogenic (able to cause disease). The body produces plasma and memory B cells, which remain in the body for years and provide a secondary response.
Formation of antigen–antibody complexes also stimulates the production of complement; these are plasma proteins which also bind to the complex and destroy the pathogen and stimulates phagocytosis by coating the pathogen.
Examples of cell signalling
Pathogen has antigens on its cell surface membrane – signalling foreign
Infected body cells produce lysosomes which damage the pathogen. Bits of pathogen become embedded in the host plasma membrane and can be detected by the immune system and attract killer T cells.
Macrophages presenting antigen on their plasma membrane
Cells releasing cytokines to instruct target cells
Cell signalling: communication between cells that allow effective coordination of a response.
Macrophages release monokines, which attract neutrophils by chemotaxis and stimulate production of plasma B cells.
Interleukins released by B cells, T cells and macrophages stimulate their production. Interferon released by cells inhibits viral replication and stimulates T killer cell activity.
Disease
Antigenic material used in vaccination
Tetanus
Modified toxin (inactivated toxin)
Measles
Attenuated virus (can’t replicate as quickly as pathogenic form) but is living TB
Attenuated bacteria (can’t replicate as quickly as pathogenic form) but is living
Smallpox
Cholera
Inactivated bacteria and toxin
Hep. B
Bacteria modified to make the viral antigen
Whooping cough
Dead bacteria

11. What is percentage cover?
What is herd vaccination?
What is ring vaccination?

12. Ring vaccination – vaccinating all the individuals in the immediate vicinity of a new case of infection (often used to control the spread of disease in livestock).
Herd vaccination – a large proportion of the population is vaccinated so that the chance that individuals who are not immune will get an infectious disease is lowered.
Percentage cover – the percentage of the population that must be vaccinated to prevent an epidemic.