Immunology and public health Flashcards
What types can non specific defences be?
Physical and chemical
What do epithelial cells do?
Form a physical barrier
Where are epithelial cells found?
In the skin and inner linings of the digestive and respiratory systems
Why are chemical secretions produced?
To prevent invading pathogens
Give examples of areas of secretions
Tears, saliva and stomach acid
What is a pathogen?
A bacterium, virus or other organism
What can a pathogen cause?
A disease
Describe the inflammatory response
Histamine is released by mast cells causing vasodilation and increased capillary permeability
Increased blood flow leads to an accumulation of phagocytes and clotting elements at the site of infection
What do phagocytes do?
They recognise pathogens and destroy them by phagocytosis
What does phagocytosis involve?
engulfing of pathogens and their destruction by digestive enzymes contained in lysosomes
What do phagocytes release?
Cytokines
What does cytokines attract?
More phagocytes to the site of infection
What are cytokines?
Protein molecules
What do cytokines act as?
A signal to specific white blood cells causing them to accumulate at the site of infection
