Lecture 3 Flashcards
What is asthma?
Chronic inflammatory disorder of the airway
What is asthma associated with?
Variable airflow obstruction Andy increase airway response to a variety of stimuli - hyper responsiveness
What is PEFR?
Peak expiratory flow rate
What is FEV1?
Forced expiratory volume in 1 second
Name the two lung function tests
PEFR and FEV1
Name the mechanisms of hyperresponsiveness
Increased smooth muscle contractibility - smooth muscle hyperplasia/hypertrophy
Increased excitatory nerve activity
Decreased bronchodilator activity
Inflammation - epithelial damage and exposure of sensory nerves, oedema and secretion leading to decreased luminal diameter
Define hyperplasia
More muscle cells more contraction
Define hypertrophy
Bigger muscle cells
What does Ach act on?
M3 receptors
What does Ach cause?
Bronchoconstriction
Name two muscarinic antagonists
Ipatropium and tiptropium
What is ipatripium used to treat?
Irritant induced bronchospasm, by inhalation and nebuliser, asthma, bronchitis and COPD
How does bronchidilation occur?
As a result of circulating adrenaline in the body
What does circulating adrenaline act on?
On beta adrenoceptors on airway smooth muscle
What’ve other neurotransmitters cause bronchodilation?
Inhibitory non-adrenergic and non-cholinergic transmitters
Dilator neuropeptides - CGRP and VIP
Neuronally derived NO
