10. Disease and Immunity

10.1 Diseases and immunity

Core

  • Define pathogen as a disease-causing organism

  • Define transmissible disease as a disease in which the pathogen can be passed from one host to another

  • State that the pathogen for a transmissible disease may be transmitted either through direct contact, e.g. through blood or other body fluids, or indirectly, e.g. from contaminated surfaces or food, from animals, or from the air

  • State that the body has defences:

– mechanical barriers, limited to skin and hairs in the nose

– chemical barriers, limited to mucus and stomach acid

– cells, limited to phagocytosis and antibody production by white blood cells

– which can be enhanced by vaccination

Supplement

  • State that antibodies lock on to antigens leading to direct destruction of pathogens, or marking of pathogens for destruction by phagocytes

  • Explain how each pathogen has its own antigens, which have specific shapes, so specific antibodies which fit the specific shapes of the antigens are needed

  • Define active immunity as defence against a pathogen by antibody production in the body

  • Explain that active immunity is gained after an infection by a pathogen, or by vaccination

  • Explain the process of vaccination:

– harmless pathogen given which has antigens

– antigens trigger an immune response by lymphocytes which produce antibodies

– memory cells are produced that give long-term immunity

Immune system Intro

Disease and immunity Part 1

Defences against pathogens

Vaccines

Lymphocytes and Phagocytes

10.1 Diseases and immunity continued

Core

  • Explain the importance of hygienic food preparation, good personal hygiene, waste disposal and sewage treatment in controlling the spread of disease

Supplement

  • Explain the role of vaccination in controlling the spread of diseases

  • Explain that passive immunity is short-term defence against a pathogen by antibodies acquired from another individual, e.g. mother to infant

  • State that memory cells are not produced in passive immunity

  • Explain the importance of passive immunity for breast-fed infants

  • State that some diseases are caused by the immune system targeting and destroying body cells, limited to type 1 diabetes

Disease and Immunity Part 2