Non-specific Body Defences Flashcards
What is a physical defence?
Closely packed epithelial cells found on the surface of skin and lining the body’s digestive and respiratory system offer a physical barrier against bacteria and viruses
What is a chemical defence?
Secretions including tears, saliva, mucus and stomach acid are produced against invading pathogens (disease causing microorganism)
An inflammatory response is caused by what?
By a physical injury such as a cut or invasion of microorganisms
Following injury, mast cells found in the connective tissue become activated releasing large quantitates of histamine, a chemical which causes vasodilation and capillaries to become more permeable
The increased blood flow leads to accumulation of phagocytes and clotting elements at the site of infection
What do phagocytes do?
They recognize pathogens, engulf them and destroy them using digestive enzymes contained in lysosomes through phagocytosis
They also release cytokines (protein molecules which act as a signal) attracting more phagocytes to area of infection
