I: Innate Immunity Flashcards
Describe the 4 components of the Innate Immune system.
- Physical barriers
- Physiological barriers
- Chemical barriers
- Biological barriers
Name some physical barriers to pathogens.
- Skin
- Mucous Membranes
- Bronchial cilia
Name some physiological barriers to pathogens.
- Diarrhoea
- Vomiting
- Coughing
- Sneezing
Name some chemical barriers to pathogens.
- Low pH
- Antimicrobial molecules (e.g. IgA, Lysozyme, mucus ect)
Name some biological barriers to pathogens.
- Normal flora
What is the role of macrophages in preventing infection?
- Ingest and destroy microbes (phagocytosis)
- Produce cytokines
- Antigen presentation to T cells
What is the role of monocytes in preventing infection?
Recruited to site of infection and differentiate into macrophages.
What is the role of neutrophils in preventing infection?
Ingest and destroy pathogenic bacteria
What is the role of eosinophils in preventing infection?
Defense against multi-cellular parasites
What is the role of natural killer cells in preventing infection?
Kill all abnormal host cells (virus infected or malignant)
What is the role of dendritic cells in preventing infection?
Present microbial antigens to T cells (acquired immunity)
What are opsonins?
A coating of proteins that bind to the microbial surfaces leading to enhanced attachment of phagocytes and clearance microbes.
Name 2 acute phase proteins.
- CRP
- MBL (Mannose-binding lectin)
Name 3 encapsulated bacteria.
- Neisseria meningitidis
- Streptococcus pneumoniae
- Haemophilus influenza B
What is respiratory burst?
The intracelluar killing mechanism by which a phagocyte uses the oxygen-dependent pathway to destroy a microorganism.
