chap 10- Diseases and immunity Flashcards
Pathogen
– a disease causing organism
Transmissible disease
disease in which the pathogen can be passed from one host to another
Active immunity
defense against a pathogen by antibody production in the body
Passive immunity
short term defense against a pathogen by antibodies acquired from another individual (mother to infant)
How can pathogens be transferred?
- Direct contact (e.g. blood or body fluids)
- Indirectly (e.g. contaminated surfaces, food, in the air)
Describe the body’s defenses to pathogens
- Mechanical barriers (e.g. skin and hair)
- Chemical barriers (e.g stomach acid)
- White blood cells (e.g. phagocytes and antibody production which can be enhanced by
vaccination)
How do antibodies work?
- Bind to antigens
- All pathogens have their own antigens with specific shape
- Antibodies are specific to shape of antigen
- Cause direct destruction
- OR marks them for destruction by other cells
how is active immunity gained
Gained after infection or vaccination
How do vaccines work?
- Harmless pathogen given which has antigens
- Antigens trigger immune response
- Lymphocytes produce antibodies
- Memory cells produced for long term immunity
- Needed to control disease spread
- More people immune, less pathogen created, less spread = herd immunity
Method to reduce disease
1)Hygienic food preparation -Contaminated food can contain pathogens or toxins
that cause food poisoning
2)Good personal hygiene- Reduces chances of contracting or transmitting disease
3)Waste disposal -Waste and rubbish is source of infection
4) Sewage treatment -Reduce risk from contaminated human waste
Explain passive immunity
- Short term defence against pathogens
- Antibodies acquired from another individual
- Memory cells are NOT produced
- Important to breast fed infants - antibodies passed to infant in mother’s milk, required as
infants have undeveloped immune systems
What causes type-1 diabetes
- Immune system targeting and destroying own body cells
