Diseases and Immunity Flashcards
What are pathogens?
A pathogen is a disease-causing organism
What is meant by transmissible diseases?
Pathogens that are passed on from one host to another.
What is direct contact?
When the pathogen is passed directly from one host to another by transfer of body fluids such as blood or semen (eg HIV, gonorrhoea, hepatitis B & C).
What is indirect contact?
When the pathogen leaves the host and is carried in some way to another, uninfected individual.
What are the mechanical barriers?
Skin and hair in the nose.
What are the chemical barriers?
Mucus and stomach acid.
What is phagocytosis?
engulfing and digesting pathogenic cells.
What is active immunity?
Making antibodies and developing memory cells for future response to infection is known as active immunity.
What is passive immunity?
This is when ready-made antibodies, from another source, are introduced to the body.
What is an antigen?
a chemical found on the surface of a cell.
What is an antibody?
A chemical made by lymphocytes that is complementary to an antigen and, when attached, clumps them together and signals the cells they are on for destruction.
What is an antibiotic?
A drug that slows down or stops the growth of bacteria.
What is vaccination?
Vaccinations give protection against specific diseases and boost the body’s defence against infection from pathogens without the need to be exposed to dangerous diseases that can lead to death. The level of protection in a population depends on the proportion of people vaccinated
