Non specific body defences Flashcards
What is a pathogen
A bacterium, virus or other organisms that can cause disease
What non specific defences does the body use to protect itself from pathogens
physical and chemical defences
inflammatory response
phagocytes
What are epithelial cells
cells that line organs and glands in the body
epithelial cells form a physical barrier and produce secretions against invading pathogens
Where are these closely packed epithelial cells found in the body
in the skin and inner linings of the digestive and respiratory system
How does the skin physically protect the body from pathogens
epithelial cells in the skin form a physical barrier that prevents the entry of pathogens
How does saliva in the mouth help to protect the body
saliva contains enzymes that destroy some pathogens
How do epithelial cells in the windpipe help to protect the body
produce mucus to stop pathogens
How do epithelial cells in the eyes help to protect the body
tears contain lysozyme to digest cell walls of bacteria
How do epithelial cells in the stomach help to protect the body
epithelial cells in the stomach produce acid that kill pathogens
What are mast cells
cell present in connective tissue throughout the body, they are similar to white blood cells
How do mast cells respond to inflammatory response
Mast cells produce histamine
What affect does histamine have
Histamine causes vasodilation and capillaries to become more permeable
this increases blood flow to the injured site resulting in the area becomes red and inflamed
What is the role of clotting chemicals/elements
They trigger a cascade of events that leads to blood clotting
What are phagocytes
a type of white blood cell
Give two examples of a pathogen
Bacteria and viruses
Why do phagocytes respond to pathogens
Phagocytes recognise non self antigens of pathogens
What is an antigen
any foreign molecule that results in an immune response
How do phagocytes destroy the pathogens
phagocytes recognise pathogens and destroy them by phagocytosis
phagocytes engulf the pathogen
phagocyte contains lysozymes
lysozymes contain digestive enzymes and destroy pathogen
When phagocytes destroy pathogens they also release protein molecules chemicals called what
cytokines
What is the role of cytokines
Cytokines act as a signal to specific white blood cells causing them to accumulate at the site of infection
What do phagocytes do
release cytokines which attract more phagocytes to the site of infection
What does the increased blood flow caused by mast cells lead to
an accumulation of phagocytes and clotting elements at the site of infection
Give examples of a chemical secretions produced against invading pathogens.
tears
saliva
mucus
stomach acid
