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Keeping healthy

Illness can be caused by many different things

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Pathogens

Pathogens are dieses causing micro ­ organisms

Different types of pathogens

Fungi - Athletes foot
Viruses ­ Common cold or influenza
Bacteria ­ Cholera
Protozoa ­ Malaria or dysentery

Ways pathogens can enter the body

Inhalation
Eating or drinking ­ something that is contaminated
Through the sink
Sexually
By…

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and carries disease e.g. mosquito




Defences

Skin ­ natural barrier
Respiratory system ­ Mucus traps micro ­ organisms and
cilia moves mucus up to the mouth
Stomach ­ Produces hydrochloric acid ( CHL ) which kills
micro ­ organisms on food
Blood clots ­ around a cut to prevent microbes…

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White Blood Cells

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The two main types of white blood cell found in the human
bloodstream. The dark object in each of the cells is the
nucleus.

How blood cells work

1. This white blood cell recognises bacteria




2. Antibodies are produced by white blood cell


3. Antibodies stick bacteria together




4. A…

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How antibodies attack antigens




Active Immunity

After the body has made the antibody it remembers it
If the same pathogens enter the body again the antibodies
needed can be produced more quickly
As a result you do not become ill

Passive Immunity

In a life threatening situation the doctor can…

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Benefits

1. Protects you against a disease which could kill or cause
disability ­ Polio and measles
2. If everyone is vaccinated the diseases cannot spread and
eventually dies out ­ smallpox

Risks

1. An individual could have a bad reaction to the vaccine

Treatment

Antibodies can be used to…

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Nets can be used at night to stop mosquitoes from reaching
people ­ also water surfaces can be sprayed with oil to prevent
larvae from breathing.




Deficiency diseases

Protein gives you kwashiorkor
Iron gives you anaemia
Vitamin C gives you scurvy
Calcium and Vitamin D gives you weak bones

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Diabetes

This is caused by organ malfunction
The pancreas stops producing insulin

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Cancer

Cancer occurs when the body cells divide uncontrollably to
produce a mass of cells called a tumour
Some tumours stop growing and are therefore benign
( safe )
It is tumours that continue to grow and spread that are
dangerous, these are malignant

It is possible to reduce the…

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