cell recognition and the imune system Flashcards
Pathogen
Harmful microbe
Humoral immunity
is so named because it involves substances found in the humours or body fluids.
Immunity
The body’s ability to fight off a pathogen
ineffective immunity
immunity is reduced in the young, elderly and those in ill health
Non-Specific Immunity
Immediate and affects all pathogens e.g. Physical barrier such as skin, phagocytosis
Specific Immunity
Slower, more specific and longer lasting. Specific to a type of pathogen. Cell-mediated: T lymphocyte or Humoral response
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phagocytosis
Where a phagocyte cell engulphs and destroys a pathogen. 5 Stages:
- Attracted: phagocyte moves towards the chemical products excreted by the pathogen
- Attached: receptors on phagocyte to chemicals on the pathogen
- Engulphed: phagocyte forms phagosome around pathogen
- Hydrolyse: the lysosome release enzymes / lysozyme, to digest the pathogen
- Absorped: debris absorbed by phagocyte
Humour
Latin for moisture: The four fluids were blood, phlegm, yellow bile, and black bile.
lymphocyte
White blood cells produced in the bone marrow. Immature lymphocytes that react to self are destroyed (apoptosis)
T Lymphocyte
Cell mediated response - phagocytosis
B Lymphocyte
Humoral response
Self / Non-self recognition
Cell specific molecules, e.g. proteins on surface can be identified
PAST
4 Examples of non-self
Pathogens like HIV
Abnormal self cells - cancer
Same species non self - human kidney transplant
Toxins - excreted by pathogens
1st Stage of Immune Response
Identify threat
Clonal Selection
The specific lymphocyte that matches the pathogen is replicated to form sufficient numbers to be effective.
