Ch. 10 Immunity and disease !!! Flashcards
What is a pathogen?
A microorganism that causes disease
What groups do pathogen belong to?
Bacteria, virus, protoctists, fungi
What is a host?
Organism in which the pathogen lives and breeds
What does it mean when a disease is transmissible?
Can be passed from host to another host
What are toxins?
A poisonous substance often caused by pathogens
What are symptoms?
Features that you experience when you have a disease
What is infection?
The entry of a pathogen into the body of an host
What is transmission?
Movement of pathogen from host to another
How are pathogen passed?
- Direct contact
- Indirect transmission
What is direct contact?
Disease passed through infected person touching an uninfected one
What is indirect transmission?
- Breathing droplets
- Touching a surface an infected person has touched
- Eating food with pathogens
- Contact with animals carrying pathogen
What are defensive mechanisms against pathogens and how do they help?
- Skin –> prevents pathogens from entering
- Mucus –> traps bacteria
- Nose/mouth –> if something tastes bad/ smells bad we dont eat it
- Hair nose –> filter out particle
- Stomach –> contains hydrochloric acid
How to prevent pathogens from spreading?
- Clean water supply
- Food hygiene (keep bacteria away, keep animals away, dont keep at room temperature)
- Personal hygiene
- Water disposal and sewage treatment
What is cholera caused by?
By a bacterium
How does cholera work?
- Bacteria attach to walls of alimentary canal
- Bacteria releases toxin
- Toxin causes Chlorine ions to multiply
- More chlorine ions = lower water potential
- Water from blood moves to alimentary canal (OSMOSIS)
What are lymphocytes?
One type of blood cells
What do lymphocytes do?
Produce antibodies
What are antibodies?
Proteins with a particular shape
What are antibodies complimentary to?
Another molecule called an antigen
What are antigens?
Molecules found on the outside of a pathogen
What do antibodies molecules do?
Bind with the pathogen and either directly kill it or stick to the pathogen
How does it work?
Pathogen meets lumphocyte
Lymphocyte –> mitosis
New lymphocytes –> secrete antibody
What is the immune response?
The reaction of a body to the presence of an antigen
What are memory cells?
Lymphocyte cells which did not secrete antibody immediately but will when pathogen enters the body again