Download HOW OUR IMMUNE SYSTEM FUNCTIONS

HOW OUR
IMMUNE SYSTEM
FUNCTIONS
ACTIVIT Y SHEET
INTRODUCTION
T H I S I S ON E OF T WO ACTIVITIES THAT CA N B E U S E D W I TH THE A N I MATI O NS
I M MUN EC RAF T, LOOP, A ND BAT TLE O F B LI S TE R . I N E ACH CA S E R E S E A R CH E R S
AR E WOR K I N G TO UNDERSTA ND M O R E A B O U T HOW O U R B O DI E S R E S P O ND TO
I NF EC T I ON AND HOW TO FIGHT AU TO I MMU N E DI S E A S E S S U CH A S R HE U M ATO ID
AR T H R I T I S W HERE THE BODY ’ S IM MU N E SYS TE M TU R N S O N I TS E LF.
AIMS
TO BECOME FA MILIA R WITH THE CE LL T Y P E S THAT A R E I MP O R TA N T
I N T H E I MMU NE SYSTEM
TO APPLY K NOWLED GE OF THE I MMU N E R E S P O N S E TO E XP L A I N W HAT
I S HAPPEN I NG AT A CELLU L A R LE V E L A S THE B O DY I S I N VA DE D A N D
CO UN T ER S WITH A N AT TACK OF I TS OW N
MATERIAL S
D OW N LOAD THE SET OF CA RDS D E V E LO P E D BY
M AN C HES T ER UNIVERSIT Y IMMU N O LO GY GR O U P :
http://www.mig.ls.manchester.ac.uk/documents/toptrumps.pdf
STARTER
AS K T H E F OL LOWING QUESTION AN D R ECO R D THE A N S W E R S .
“How many parts of the immune system can you name?”
A GR EAT VI S UA L RESOURCE CA N B E F O U N D HE R E :
http://www.livescience.com/38028-how-the-human-body-s-immune-system-works-infographic.
html
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METHOD
T H ES E C AN BE U SED WITH TO PL AY CE LL TO P
T R UMPS US I NG THE INSTRUCTION S I N THE DOW N LOA D.
The cards can also be used to reinforce students’ knowledge of cell types, the chronology of
the immune response and where things happen in the body.
For example, give students one of these case studies and ask them to use as many cards as
possible to explain the infection scenario.
CASE 1
You get a splinter in your finger. You pull it out, but later that evening your finger becomes
swollen and red. A few days later the entire hand is swollen, the pain is intense and you develop
a fever. What is going on?
CASE 2
As a child you received an emergency injection of antivenom to treat a snake bite. The drug was
horse serum with antibiotics. The doctor told you that this procedure could never be repeated or
boosted. Why?
CASE 3
Your grandmother had a flu vaccination in November but a month later at Christmas came down
with the flu. What happened?
CASE 4
You are fed up with getting colds every winter and ask the doctor for antibiotics or a vaccine but
are told no you can’t have either. Why?
DISCUSSION
W HAT AR E S O M E WAYS THAT INFECTI O U S DI S E A S E S
AR E T RAN S MIT TED FROM ONE PE R S O N TO A N OTHE R ?
Droplets in the air (e.g. cold, flu, tuberculosis)
Via food or water (e.g. Salmonella, food poisoning)
Via mosquitoes, ticks (e.g. malaria, West Nile virus, Denge fever)
Physical contact (e.g. conjunctivitis, herpes, chickenpox, sexually transmitted diseases)
You can catch an infectious disease due to a virus by getting it on your hands and then touching
your mouth or eyes or eating food you have touched with unwashed hands.
The AIDS virus is not spread like this but can be transmitted from one person to another in other
ways such as by having vaginal or anal intercourse with a person who is infected with HIV, by
sharing needles with someone who is infected with HIV, from an infected mother to her baby
during pregnancy, birth or nursing or from a blood transfusion with contaminated blood.
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W HAT AR E S O M E WAYS YOU CA N P R E V E N T
T H E S PR EAD OF A N INFECTIOU S DI S E A S E ?
Avoid close contact with people who are infected
Use tissues if you have a cold or flu and throw them away
Wash hands especially before eating, after using toilet, or after contact
with someone who has an infection
Don’t touch other people’s blood or body fluids (e.g. soiled tissues from
someone who has a cold)
Don’t share toothbrushes, eating utensils etc
Eat nutritious food to keep the body healthy
H OW MI GHT THE SPREA D OF A IRB O R N E DI S E A S E S DI F F E R F R O M THE
S P READ OF DISEA SES THAT DEPEN D O N P E R S O N -TO - P E R S O N CO N TACT?
Airborne diseases can be spread to multiple people at the same time and can be spread
to people who are nearby but not in direct contact.
I N A DDI T I ON TO EXPOSURE TO GE R MS ( BACTE R I A O R V I R U S E S ) , W HAT OT H E R
FAC TOR S I N F LUENCE YOU R RISK O F GE T TI N G A N I N F ECTI O U S DI S E A S E ? WH AT
D E FEN C ES DO ES YOU R BODY HAV E THAT CA N P R E V E N T YO U F R O M GE T TING
S I C K , EVEN WHEN YOU HAVE BEEN E XP O S E D TO GE R MS ?
Susceptibility to infection can be reduced by good hygiene practices, such as washing your
hands after possible exposure to pathogens before touching your eyes, mouth or mucous
membranes where infection may occur. Susceptibility may be increased by a weak immune
system due to age, previous illness, inadequate nutrition etc. Resistance to a specific infectious
disease can be increased if you have had this infectious disease previously or been vaccinated
against this disease. Important defences include barriers such as the skin and mucous
membranes, chemicals such as acid in the stomach, inflammation and phagocytic cells.
The specific immune system also contributes to defences against infection, but more slowly.
ON CE YOU H AVE CAU GHT A COLD O R F LU, YO U DO N OT S TAY S I CK F O R E V E R .
H OW DOES YO U R BODY EVENTUA LLY GE T R I D O F THE V I R U S E S THAT CAUS E
A COL D OR F LU?
If a cold or flu virus gets past the first set of defences (such as the skin and mucous membranes)
and infects your body, your immune system is stimulated to produce specific immune system
cells (B cells and T cells) that can effectively fight the particular virus that has infected your body.
This response takes time, especially the first time you are exposed to a specific virus, so you are
sick with a cold or flu until the specific immune cells become effective enough to rid your body
of the virus.
After an infection, your body will have memory cells which can produce a rapid defence if you
are exposed to the same virus a second time, so you will be able to fight off a second infection
rapidly and effectively and the level of viruses will be kept low so that you may never even feel
sick. A vaccination induces the production of memory cells which can mount a rapid defence
against that particular infection.
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W HY I S A PERSON WITH A N HIV IN F ECTI O N U N A B LE TO GE T R I D O F THI S
I NF EC T I ON T HE WAY A PERSON C A N GE T R I D O F A N I N F ECTI O N W I TH A
CO L D OR F LU VIRUS?
In almost every case, a person who becomes infected with the HIV virus is infected for the rest of
his or her life. With highly effective modern medical treatment, a person may survive a long time
with an HIV infection. However, an untreated HIV-infected individual is very likely to eventually
develop AIDS and die. There are many reasons why our bodies are unable to get rid of an HIV
infection. One important reason is that HIV infects an important type of T cell, the Helper T cell,
which is crucial in mobilising other immune cells to fight infection. As more and more Helper
T cells are killed by HIV infection, the body becomes less and less able to fight infections,
including HIV infection.
Another reason why the body cannot get rid of HIV infection is that the genetic material of
the HIV virus is incorporated in the DNA of infected cells, and some of these infected cells
can survive undetected by the immune system over long periods of time. Scientists are very
interested in the genetic and immune system differences of the tiny number of people whose
bodies appear to be able to control or eliminate HIV infection.
EXTENSION QUESTIONS
T H ES E C AN BE U SED WITHIN THE S E S S I O N TO S TI MU L ATE
D E BAT E OR F O R HOM EWORK / INDE P E N DE N T S TU DY TA S KS .
What are the consequences of people living for longer on the treatment of
infectious diseases?
Which genes vary the most between people, the ones that influence the
way we look or the ones that shape our immune system?
Can you think of other health areas, outside of infectious diseases, where the
immune system plays a vital role?
Severe combined immunodeficiency (SCID) mice have a mutation which stops
their immune system maturing. They are routinely used to study immune diseases.
How does their mutation affect the way they are kept?
OTHER RESOURCES
M AN C HES T ER IMMU NOLOGY GRO U P
H AV E OT HER RESOURCES AT:
http://www.mig.ls.manchester.ac.uk/resources/
G L AS G OW S CIENCE CENTRE HA S A N O N LI N E GA ME I N W HI CH
PL AYER S S EEK TO STEM THE SPRE A D O F THE F LU V I R U S AT:
http://www.glasgowsciencecentre.org/online/epidemic-emergency.html
T H E C EN T R E OF THE CELL HAVE LOTS O F R E S O U R CE S :
www.centreofthecell.org/learn-play/games/
http://www.centreofthecell.org/wp-content/uploads/New_Vaccines.pdf
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T H E ABPI EDUCATIONA L RESOU RCE PAGE S O N
I M MUN I T Y AND VACCINATIONS CA N B E F O U N D AT:
http://www.abpischools.org.uk/page/modules/infectiousdiseases_immunity/index.cfm?coSiteNavigation_allTopic=1
A THOR OUG H BUT ACCESSIBLE RE V I E W O F THE I MMU N E
SYST EM AN D HOW IT WORKS CA N B E DOW N LOA DE D HE R E :
http://www.imgt.org/IMGTeducation/Tutorials/ImmuneSystem/UK/the_immune_system.pdf
SYLL ABUS LINKS FOR
A- LEVEL BIOLOGY
AQA
Topic 2 Cells
E D E XC EL SALTERS NUFFIELD
Topic 6 Immunity Infection and Forensics
E D E XC EL B
Topic 2 Cells, Viruses and Reproduction of living things
Topic 6 Microbiology and pathogens
OC R A
Module 4 Biodiversity, evolution and disease
OC R B
Module 3 Cell division, development and disease control
WJ EC
Component 3 option Immunology and Disease
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