Biology, disease, defence and treatment

Alexander Fleming

Fungus

Destroy bacteria or stop its growth

Only work on bacteria and fungi
Don’t kill viruses

MRSA
Over-use of antibiotics

Keeping hospital wards clean
Hand washing

Pathogens

Fungi, protists, bacteria and viruses

Contact
Aerosol
Bodily fluids
Water
Insects
Contaminated food

Skin flora- bacteria making it difficult for pathogens to become established
Intact skin- barrier, blood clots around wounds
Stomach acid+lysozome- in tears, protect where skin isn’t

White blood cells will respond

Microbes haven proteins called antigens on their surface, phagocyte recognises it and engulfs it.

Enzymes inside digest the microorganism

Lymphocytes

Neutralise any toxins produced by invading microbes

antigen

They have complementary shapes to the specific antigen on the microorganisms surface

Phagocyte marks them for destruction
Clumps microbes together so many can be destroyed at once
Destructs the microbe

Because thalidomide wasn’t tested- caused babies born to have birth defects

To avoid side effects

Testing on lab grown human cells
Testing on animals
Testing on healthy human volunteers

Testing on a small group of patients

Placebo
Blind trial
Double blind trial

Placebo used instead of a drug in trial

Patients don’t know if they’ve been given the drug or the placebo, but the doctors know

Patients or doctors dont know what patients have been given the drug or the placebo

1- Lymphocyte recognises antigen
2- Lymphocyte produces specific antibody
3- cell that makes antibody divides
4- microorganism killed, clone cells die, memory cells left
5- if microbe come again, antibodies produce faster before symptoms arise- immunity

Through vaccines, they have dead virus inside them