Asthma Flashcards
What causes reversible episodes of a/w obstruction
inflammation and hyperactivity
What causes chronic inflammation of the a/w
hyper responsive airway and recurrent, reversible bronchospasms
Aetiology of Asthma
complex trait (genetic component with an environmental factor
What brings about episode of asthma
HS to stimuli such as allergens, cold, exercise, odours
Patho of Asthma
Trigger - increase HS - 2 phased response
What are the two phases called
Acute- phase response and Late-phase response
What happens when exposure to an allergen occurs in the Acute-phase response?
allergen binds to IgE on the mast cell - mast cell degranulates - meditators are release - inflammation occurs
How do allergens enter the submucosa
intercellular junctions open
what causes edema of the airway
increased permeability and increased mucus secretions
bronchospasm is stimulated by what ?
PNS
Late-Phase Response: peaks and lasts how long ?
peaks 4-8hrs and lasts days to weeks
late-phase is a what kind of cycle?
self sustaining cycle of exacerbation
an influx of inflammation cells causes what?
epithelial damage, decrease mucocilliary function, hyper responsive airway (now responds to new triggers more frequent and severe)
Bronchoconstriction via BLANK
alpha adrenergic receptors
Bronchodilation via BLANK
beta adrenergic receptors