Host defence in the Lung Flashcards
Define innate immunity
Immunity that doesn’t require prior exposure
Phagocytosis and Inflammation
Describe mechanism of inflammation
1) Vasodilation leads to exudation of
plasma (inc AB’s –> Activate cascades)
2) Neutrophils and monocytes migrate into tissue
Why is inflammation simultaneously good and bad?
G: Defence against infection and hostile environment
B: Many die of disease caused by inflammation
What are alveolar macrophages derived from?
Monocytes, act as resident lung phagocyte and coordinate immune response
Why are the lungs at increased risk of inflammation?
1) Huge area in contact with external environment
2) Lung contains majority of WBC’s at any one time
Causative agents of chronic inflammation?
Persistent acute inflammation, autoimmune reactions, persistent foreign bodies
How do we recognise pathogens never been seen?
Pattern Recognition Receptors (PRR’s)
What are causative agents of acute inflammation?
Pathogens and damaged tissue
What are the non-respiratory functions of lungs?
1) Synthesis of vasoactive substances
2) Lung defence
3) Speech vomiting defecation
Function of epithelial barrier in host defense?
1) Moisten and protect airway
2) Function as barrier to pathogens and foreign matter
Describe muco-ciliary escalator?
1) Mucosal secretion from goblet, and S-M glands both trap particulate matter
2)Beating cilia transport mucus up the RT
(Acts to prevent infection)
What is coughing?
Expulsive reflex protecting lungs and respiratory passages from foreign bodies
Why is immune function in ageing lung less effective?
Less protective mucus and sputum clearance less effective
Main cell in acute inflammation?
Neutrophil
What are 4 non-immune host defence mechanisms?
1) Mucus
2) Muco-ciliary escalator
3) Epithelium
4) Cough
