1. B2 Keeping Healthy Revision

2. B2 yum

3. B2 Body defence 1 st 2 nd yum Immunity Body defence Risk antibodies

4. B2 Keeping Healthy Pathogens viruses bacteria fungi First line of defence Eyes: tears antiseptic Ears: wax is antibacterial Stomach: contains acid Skin: sweat glands Second line of defence White blood cells Phagocytes “eat” pathogens antibodies clump to pathogens immobilising them The body takes time to make new antibodies; so you get sick Risk with all medication When you recover you have memory cells Vaccines force the white blood cells to make antibodies, when you meet the real pathogen you don’t get sick Reduce Risk Clinical trials: consider ethics Blind trial: patient doesn't know if drug is a placebo Double Blind trial: patient or doctor doesn't know if drug is a placebo Placebo: no active chemicals Immunity Drugs Antibiotics: don’t work on viruses Heart disease: risk Smoking Excess alcohol Unhealthy diet Obesity

5. Describe what's happening in the picture

6. Describe what’s happening in the picture Give as much detail as possible Vaccine containing weakened or dead pathogens induce an immune response Sometimes there are side effects Memory cells are produced so when you come in contact with the real pathogen they produce antibodies quickly so you don’t get sick; this is immunity. Antibodies are produced. They are very specific to one type of pathogen