Non-specific Body Defenses Flashcards
What forms a physical barrier?
Epithelial cells form a physical barrier.
Where are physical barriers found?
Physical barriers ( epithelial cells that are closely packed ) are found in the skin and inner linings of the digestive and respiratory systems.
What is a physical defence?
Epithelial cells forming physical barriers.
What are chemical defences?
chemical secretions that are produced against invading pathogens
What are the four chemical secretions involved in the chemical defence?
Tears, Saliva, Mucus, Stomach Acid
What is a pathogen?
A pathogen is a bacterium, virus or other organism that can cause disease.
What releases histamine?
Mast cells release histamine.
What does histamine cause?
Histamine causes vasodilation and increased capillary permeability
What does histamine do to prevent infection?
Histamine causes vasodilation and increased capillary permeability, this increases blood flow which leads to an accumulation of phagocytes and clotting elements at the site of infection.
What are phagocytes?
Phagocytes are a type of white blood cell involved in the inflammatory response
What is the function of phagocytes?
Phagocytes recognise antigens on a pathogen and destroy them via phagocytosis
What is phagocytosis?
Phagocytosis involves the engulfing of pathogens and their destruction by digestive enzymes contained in lysosomes
What do phagocytes release in order to attract more phagocytes to the site of infection?
Phagocytes release cytokines to attract from phagocytes to the site of infection
What are cytokines?
Cytokines are protein molecules that act as a signal to specific white blood cells causing them to accumulate at the site of infection.
