Asthma Flashcards
What are the two types of lung diseases?
Obstructive and restrictive
Obstructive is problems with expiration and restrictive is problems with inspiration
Name some obstructive lung diseases
Asthma
Chronic bronchitis
Emphysema
Bronchiectasis
What does inflammation of the airways cause?
Smooth muscle contraction
Mucus hypersecretion
Results of Smooth muscle contraction
Mucus hypersecretion?
Narrowed lumen therefire increased airway resistance
decreased airdlow
What are the two stages of allergic asthma?
- Sensitisation - immune system first encounters allergen and develops adaptive immune response
- Allergic response - allergen is re-encountered, triggering the adaptive response primed during sensitisation. This generates an inflammatory response within airways
This causes symptoms
Explain the innate part of sensitisation
Allergen enters immune tissue
APC’s engulf the antigen and present antigens
Native helper T cells encounter😱 activated and matures into a Th2 cell
Th2 cell interatcs with a B cell which proliferates and
Produces IgE antibodies
antibodies circulate and bind to receptors on granulocytes like mast cells
Th2 cells will also secrete ‘Th2 cytokines’ such as IL-4, IL-5 and IL-13
IL-5 in particular promotes survival of eosinophils
Allergic response explanation goooo?
Upon subsequent re-exposures, antigens within the allergen are recognised by IgE molecules bound to mast cells within the airways
Triggers degranulation
Granulocyte releases inflammatory mediators
Causes constraction of smooth muscle cell, oedema, mucus secretion
What is the immediete effect of allergic response
Rapid bronchospasm
What is airway remodelling?
Frequent long term asthma attacks leading to cycles of tissue injury and repair leading to irreverisble structural changes
What type of drugs are the most common for treating asthma?
Beta-2-agonists
How do beta-2-agonists work?
Increased production of cAMP
Activation of protein kinase A
Reduces Ca2+ mobilisation
Inducing relaxation
How are different classes of beta-2-agonists differentiated?
By their duration of action
short acting beta agonists?
Salbutamol
First line of defence
Reliever therapy
long acting beta agonists?
salmetrol or formoterol
add-on preventer treatment
in combo with inhaled corticosteroids
Why are LABA’s used with corticosteroids?
Evidence that use without increases risk of sudden DEATH!!!!!!!
Long acting muscarinic receptor antagonists?
tiotropium
Bronchodilator
Blocks acetylcholine receptors on alveolar smooth muscle
Blocks M3 which induces contraction
Name some corticosteroids
fluticasone
budesonide
What is the most effective drug for reducing allergic inflammation in asthma?
Corticosteroids
How do corticosteroids work?
By binding to glucocorticoid receptors present within the cytosol of immune and structural cells
drug-receptor complex binds to DNA, modulating transcription, translation, and protein expression.
