Preventing And Treating Disease

Question 1

Non specific defences: skin

Answer 1

Physical barrier to infection
Produced antimicrobial secretions
Microorganisms that normally live on skin prevent pathogens from growing

Question 2

Non specific defences: nose

Answer 2

Cilia and mucus trap particles in air preventing it from entering lungs
Trachea and bronchi produce mucus which is moved away from lungs to back of throat by cilia where it is expelled

Question 3

Jon specific defences: stomach

Answer 3

Produces strong acid (pH2) that destroys pathogens in mucus, foods, and drinks

Question 4

White blood cells- lymphocytes

Answer 4

Produces antitoxins that bind to toxins produced by same pathogen which neutralises toxins
Produces antibodies that target and help to destroy specific pathogens by binding to antigens (proteins) on pathogens surface

Question 5

White blood cells- phagocytes

Answer 5

Attracted to areas of infection
Phagocytes surrounds pathogen and engulfs it
Enzyme that digest and destroy pathogen are released

Question 6

Treating disease: antibiotics

Answer 6

Medicine that kills bacteria in body
Specific bacteria need to be treated by specific antibiotics
Greatly reduced deaths from infectious bacterial diseases
But antibiotic resistance strains of bacteria are emerging

Question 7

Treating viral diseases

Answer 7

Antibiotics don’t affect viruses
Drugs that kill viruses often damage body’s tissues
Painkillers treat symptoms of virus diseases but don’t kill the pathogens

Question 8

Discovering and developing new drugs

Answer 8

Traditionally extracted from plants and microorganisms
Heart digitalis comes from foxglove plants
Painkiller aspirin comes from willow tree
Penicillin comes from penicillium mold

Question 9

Drugs tested for

Answer 9

Toxicity- is it harmful
Efficacy- does it work
Dose- what amount is safe and effective to give

Question 10

Stages of clinical trials: pre clinical trials (1)

Answer 10

Drug is tested in cells, tissues and live animals

Question 11

States of clinical trials: clinical trials (2)

Answer 11

Healthy volunteers given low doses to test whether drug is safe and effective
If safe, large number of healthy volunteers and patients receive drug to find optimum dose

Question 12

Stages of clinical trials: peer review

Answer 12

Before being published, results of clinical trials will be tested and checked by independent researchers

Question 13

Double blind trials

Answer 13

Give some patients a placebo drug
Neither patients nor doctors know who has been given real drug and who’s been given placebo
Reduces biases in trial