10: Diseases and Immunity Flashcards
What is a pathogen?
A disease-causing organism
e.g. bacteria, fungi, viruses
What is a transmissible disease?
A disease in which the pathogen can be passed from one host to another
How is a pathogen transmitted? (2 ways)
- by direct contact -> includes through blood and other body fluids
- indirectly -> includes from contaminated surfaces, food, animals and air
Describe the body defences (3 ways)
- Mechanical barriers – structures that make it difficult for pathogens to get past them and into the body
EXAMPLES:
Skin -> forms a scab
Hairs in the nose -> wont let pathogens get up the nose - Chemical barriers – substances produced by the body cells that trap/kill pathogens before they can get further into the body and cause disease
EXAMPLES:
Mucus - pathogens get trapped in the mucus & can then be removed
Stomach acid - has HCL which is strong enough to kill any pathogens - Cells - white blood cells work to prevent pathogens reaching areas of the body they can replicate in
EXAMPLES:
Phagocytosis - engulfing and digesting pathogenic cells
Producing antibodies - which clump pathogenic cells together so they can’t move as easily (known as agglutination) and releasing chemicals that signal to other cells that they must be destroyed
Explain the importance of controlling the spread of disease in 1. clean water supply
- can lead to numerous waterborne diseases -> prevent with water filters & correct disposal
- spread of bacteria -> prevent by separating raw and cooked food, cover cuts, wash hands
- kill germs of disease -> shower everyday, wash your hands, use soap (kills microorganisms)
- can pollute our waste & stop us from having a clean water system -> filter out and organise
- helps pathogens breed in drainage pipes -> prevent further contamination with FILTER WASTE
Explain the importance of controlling the spread of disease in 2. hygienic food preparation
- spread of bacteria -> prevent by separating raw and cooked food, cover cuts, wash hands
- kill germs of disease -> shower everyday, wash your hands, use soap (kills microorganisms)
- can pollute our waste & stop us from having a clean water system -> filter out and organise
- helps pathogens breed in drainage pipes -> prevent further contamination with FILTER WASTE
Explain the importance of controlling the spread of disease in 3. good personal hygiene,
- kill germs of disease -> shower everyday, wash your hands, use soap (kills microorganisms)
- can pollute our waste & stop us from having a clean water system -> filter out and organise
- helps pathogens breed in drainage pipes -> prevent further contamination with FILTER WASTE
Explain the importance of controlling the spread of disease in 4. waste disposal
- can pollute our waste & stop us from having a clean water system -> filter out and organise
- helps pathogens breed in drainage pipes -> prevent further contamination with FILTER WASTE
Explain the importance of controlling the spread of disease in 5. sewage treatment
- helps pathogens breed in drainage pipes -> prevent further contamination with FILTER WASTE
What is active immunity
A defense against a pathogen by antibody production in the body
What does each pathogen have?
Its own antigens which have specific shapes
What is are antibodies?
Proteins that bind to antigens leading to a direct destruction of pathogens or marking of pathogens for destruction by phagocytes
What do specific antibodies have?
They have a complementary shape which fits specific antigens
When do you gain active immunity?
After an infection by a pathogen or by vaccination
Outline the process of vaccination
- weakened pathogens or their antigens are put into the body
- antigens stimulate an immune response by lymphocytes which produce antibodies
- memory cells are produced that give long-term immunity
