Week 3 - Innate immunity Flashcards
State 4 features of the innate immune system
- Fast
- Non-specific
- Lacks memory
- No change of intensity
State 4 features of the adaptive immunity
- Slow
- Specific
- Has memory
- Changes intensity
Name some physical barriers of first line defence
-Skin and mucous membranes
Name some physiological barriers of first line defence
- Diarrhoea
- Vomiting
- Coughing
- Sneezing
Name some chemical barriers of first line defence
- Low pH of skin and stomach
- Antimicrobials in saliva and tears
Name some biological barriers of first line defence
-Normal flora
How does normal flora act as a biological barrier?
-Completes with pathogens for attachment and resources
When would clinical situations arise from normal flora?
- When they inoculate in sites other than their origin eg via breach in barrier integrity, faecal-oral transmmission, faecal-perianal-urethra transmission, poor dental hygiene.
- Over growth in immunocomprimised
- Depletion by antibiotics
Name some innate phagocytic cells
- Macrophage
- Neutrophil
How are microbes recognised by macrophages?
- Pathogen Associated Molecular Patterns recognised by Pathogen Recognition Receptor on macrophage
- Opsonisation of pathogen allows attachment to macrophage
Name some opsonisors
- Complement (C3b, C4b)
- IgG
- CRP
- MBL
What happens after a microbe in engulfed?
-Phogosome merges with lysosome to create phagolysosome where bacteria is digested and indigestable remnants put in residual body
What chemicals act as second line innate defences?
-Cytokines and complement
What is the result of over reaction of the inflammatory response?
-Systemic Inflammatory Response Syndrome which can lead to sepsis and organ failure
What is the result of decreased functioning phagocytosis and what can this result from?
- Cannot clear infection leading to sepsis
- Immune deficiencies includling asplennic, neutropenia or decreased nuetrophil functioning (chronic granulomatosis disease)
