asthma Flashcards
(168 cards)
what is an obstructive airways disease
conditions that cause the narrowing of the large, medium-sized and small airways
what are examples of obstructive airway diseases
asthma, COPD and bronchiectasis
what do obstructive airway diseases result in
air trapping and hyperinflation
what does an obstructive airways disease look like in spirometry
↓ FEV1
↔ FVC
↓ FEV1/FVC < 70%
what is FEV1
forced expiratory volume in 1s
what is FVC
forced vital capacity
what type of disease is asthma
reversible obstructive airways disease
what is asthma caused by
inflammation, hyper-responsiveness and narrowing of the bronchial tree
where does asthma occur
in a susceptible individual secondary to a variety of stimuli
what are the characterisations of asthma
recurrent attacks of breathlessness and wheezing
what is the severity of asthma like
varies in severity and frequency from person to person
what is the diagnosis criteria for asthma
no consistent diagnostic criteria
what are some symptoms that can cause a diagnosis of asthma?
more than one wheeze, breathlessness, chest tightness and cough
variable airflow obstruction
what is the death rate like for people with asthma in the UK?
3-5 daily
where does airway inflammation occur in asthma
when a genetically susceptible individual with atopy is exposed to certain environmental factors
what is atopy
the tendency to produce high amounts of Immunoglobulin E (IgE) when exposed to small amounts of an antigen
what are features of atopic individuals
- Atopic individuals have a high prevalence of asthma, allergic rhinitis, urticaria and eczema
- Atopic individuals will demonstrate positive reactions to antigens on skin prick testing
what can cause airway inflammation
sensitisation of atopic individual
inhilation of allergen
what is the two parts of the two phase response
early reaction and late reaction
how long is the early reaction in asthma
20 min
how long is the late reaction in asthma
6-12 hours later
what regulates the inflammatory response in asthma
T-helper lymphocytes regulate the inflammatory response in asthma.
What do Th2 cells secrete in the response to asthma
Th2 cells secrete pro-inflammatory interleukins and stimulate the release of IgE antibodies by plasma cells.
What is the role of Th1 cells in the response to asthma
Th1 cells down-regulate the atopic response in asthma.