Session 8 extras Flashcards
What organ/tissue does asthma affect?
Lung airways
What are the causes of asthma?
Exercise
Cold air
Allergens - pollen, dust, mould etc.
Air pollution - cigarette smoke, chemicals
Infection
What cells are involved in the pathophysiology of asthma?
Eosinophils
Bronchial smooth muscle cells
What do eosinophils do in the pathophysiology of asthma?
Infiltrate bronchial smooth muscle,
accumulate there
Release cytotoxic mediators
What is the result of eosinophils accumulating in bronchial smooth muscle in asthma?
Mucosal odema
What is the result of eosinophils releasing cytotoxic mediators in asthma?
Damage to epithelial cells
inflammatory response
exposure of sensory nerves
What is the result of the inflammatory response in asthma?
Hyper-secretion of mucus
What is the result of sensory nerves being exposed in asthma?
Hyper-responsiveness of bronchial smooth muscle
muscle spasms
What is the effect of mucosal odema, hyper-secretion of mucus and bronchial smooth muscle spasms?
Narrowing of airways
What are two features of airway narrowing in asthma?
Variable
Reversible
What are the symptoms and signs of asthma?
Dyspnoea
Chest tightness
Wheezing
Coughing
How long does asthma last?
Chronic condition
How does the density of B2 adrenoceptors change in the lungs?
Density increases as airway diameter decreases
How does activating B2 adrenoceptors in the lungs give bronchodilation?
PKA decreases intracellular calcium conc.
decreases amount of calcium bound myosin
so bronchial smooth muscle relaxes
What are the categories of drugs used to treat asthma?
Bronchodilators - relievers
Anti-inflammatory drugs - preventers
What are the types of bronchodilators used to treat asthma?
B2 adrenoceptor agonists
Anticholinergics - M3 receptor antagonists
What are the types of anti-inflammatory drugs used to treat asthma?
Glucocorticoids
Inhibitors of mediator release
When might a short-acting B2 adrenoceptor agonist be used to treat asthma?
During an asthma attack
to give immediate bronchodilation
When might a long-acting B2 adrenoceptor agonist be used to treat asthma?
Used at night to prevent flare up of asthma
used as part of long-term treatment
Are B2 adrenoceptor agonists or M3 receptor antagonists more useful in treating asthma? Why?
B2 adrenoceptor agonists
give bronchodilation
whereas M3 receptors simply prevent bronchoconstriction caused by parasympathetic nervous system, which is not always the cause of asthma
