Pathogens and Immunity CH10 Flashcards
Define Pathogen
A pathogen is a micro organism that causes disease
What is a transmissible disease?
A disease that can be passed on
How can pathogens enter the body?
Through Direct contact and indirect transmission. Indirect Transmission is when pathogens are passed through the respiratory system, by food or water and by vectors
What is a vector?
A vector is an organism that carries a pathogen from one host to another.
What bodily defenses do humans have against pathogens?
Mechanical and Chemical Barriers
Give examples of both Mechanical and Chemical digestion
MECHANICAL - The skin is a barrier and Nostrils contain hairs which trap pathogens
CHEMICAL - The oesophugus secretes mucus which traps pathogens which are then swallowed and destroyed by HCl in the stomach
What is an antibody?
Protein molecule with a specific shape. Like an enzyme
What is an antigen?
Chemicals on the surface of a pathogen that are seen as foreign by the body
How do lymphocytes act on Pathogens?
- A lymphocyte comes into contact with the antigens that fit the shape of its antibodies
- The lymphocytes divide to form many identical cells
- The lymphocytes secrete antibodies
- The antibodies bind to the antigens and destroy them
What are memory cells?
When lymphocytes clone themselves, not all the cells make antibodies. The ones that dont are called memory cells
What is a vaccination?
A vaccination contains inactive forms of a pathogen. These are injected into the body to force your body to make memory cells. You will become immune
What is Active Immunity?
Defence against a pathogen by antibody production of the body
What is Passive Immunity?
A short Term defence against a pathogen by antibodies required from another individual
What is An Auto Immune Disease?
When lymphocytes produce antibodies that attack your own body
