Disease and immunity Flashcards
What are pathogens
Disease causing organisms
One type of disease and its meaning
Transmittable- passed from one person to another
Two ways in which pathogens are transmitted
Direct and indirect
Examples of direct contact
Infected blood, sneezing
Examples of indirect contact
Animals, water supply, contaminated food
two types of body defences
Chemical and mechanical
Examples of chemical defences
Stomach acid killing food bacteria, mucus produced by the airways that traps dust particles
Examples of mechanical defences
Nose hair to trap breathed in dust particles ,outer layer of the skin that prevents pathogens from entering
How do white blood cells produce defences
By phagocytes and lymphocytes
Describe the function of lymphocytes
Produce antibodies that stop pathogens from moving
What are antigens
A chemical found on the surface of a pathogen
Describe the function of phagocytes
Destroy bacteria by engulfing and killing them
Features of viruses
Protein coat, genetic material
How do antibodies attack pathogens
Antibodies bind to antigens preventing them from moving and allowing phagocytes to destroy them
Antibodies have complementary shapes which fit the antigen
How is active immunity gained
After an infection by antibody production
What is vaccination used for
To prevent and control the spread of diseases
Role of vaccination in controlling the spread of disease
People with no vaccinations protected more due to higher immunity from people around
Process of vaccination
Weakened pathogens
Antigens stimulating lymphocytes by an immune response to the pathogen
Memory cells produced for long term immunity
Why is personal hygiene important
To prevent the spread of disease
Role of correct food preparation
To kill bacteria and prevent contamination by filtering water
Role of correct waste disposal
To not attract flies or other insects with mixed garbage
Role of sewage treatment
For contaminated water
