Untitled Deck Flashcards
How do overcrowded living conditions affect disease transmission?
Overcrowded living conditions increase the transmission of many communicable diseases.
How do social factors affect disease transmission?
Social factors (e.g. income, occupation, area where person lives) can increase transmission of communicable diseases.
What is an example of how living conditions can increase disease transmission?
Tuberculosis (TB) is spread directly via droplet infection and indirectly because the bacteria can remain in air for long periods of time and infect new people.
Risk of TB increased in crowded living conditions.
What is an example of how social factors can increase disease transmission?
Risk of HIV infection is high in places where there’s limited access to good healthcare and health education.
What is an example of how climate can increase disease transmission?
Potato/tomato late blight is common during wet summers because the spores need water to spread.
Malaria is most common in tropical countries which are humid and hot - ideal conditions for mosquitoes (malaria vectors) to breed.
What are the animal defences that act as barriers to infection?
Skin, mucous membranes, blood clotting, inflammation, wound repair, expulsive reflexes.
What occurs if pathogens make it past the animal defences?
The immune system responds.
What is the role of the skin in animal defences?
The skin acts as a physical barrier that blocks pathogens and a chemical barrier that produces antimicrobial chemicals.
What is the role of mucous membranes in animal defences?
Mucous membranes protect body openings exposed to the environment and some secrete mucus that traps pathogens and contains antimicrobial enzymes.
What are platelets?
Fragments of cells in blood that form a series of chemical reactions when exposed to damaged blood vessels, forming blood clots.
What is the role of blood clotting in animal defences?
Blood clotting forms a mesh of protein fibres that plugs wounds, preventing pathogen entry and blood loss.
What triggers inflammation in animal defences?
Inflammation is triggered by tissue damage, causing increased permeability of blood vessels and vasodilation.
What happens during wound repair in animal defences?
The surface is repaired by outer layer of skin cells dividing and migrating to edges of the wound, and tissue below the wound contracts to bring edges close together.
What are expulsive reflexes in animal defences?
Expulsive reflexes include coughing and sneezing to expel foreign objects, including pathogens, automatically.
What are the plant defences that act as barriers to infection?
Physical plant defences include waxy cuticle, cell walls, and callose.
