pathophysiology Flashcards
what is asthma?
chronic disorder in which airways become narrowed ,leading to breathing difficulties
what can chronic asthma lead to?
- smooth muscle hyperplasia (due to a long time of bronchoconstriction)
- goblet cell metaplasia (over production of mucus)
- mucosal edema
how does allergic asthma come about?
How does eosinophilic asthma come about?
what are the overall symptoms of asthma
- wheezing
- chest tightness
- sob (dyspnea)
- cough (dry or productive)
- air trapping (hyperresonance)
- use of accessory muscles
- V/Q mismatch
- fall of systolic blood pressure of more than 10mmhg during inspiratory phase
what is the overall diagnostic test for asthma?
- arterial blood gas shows increased Co2 and decreased PH
- lung function test (spirometry) Fev1/ fvc ratio (for severity)
- history taking and symptoms
what is COPD?
it is when air is stuck in lungs and cannot be expelled , hyper inflammation
- emphysema
- chronic bronchitis
what are the risk factors of COPD
- smoking
- biomass smoke, occupational exposure
- air pollution
- genetics , female gender
- airway hyperresponsiveness
- asthma
- chronic mucus secretion
- recurrent bronchopulmonary infections
what are the clinical findings that COPD patients usually have?
- airflow limitation , air trapping
- reduced FEV/FvC ratio
- total lung capacity is normal or increased
- reduced vital capacity
what is emphysema ?
it is the destructive changes in alveolar wall and capillary beds , loss of lung elasticity and there are abnormal enlargement of the airspaces distal to terminal bronchioles
hyperinflammation of lungs
Increase in total lung capacity
what are the causes of emphysema?
- genetic disposition
- environmental factors
what is the genetic disposition of emphysema and how it cause emphysema ?
alpha antitrypsin deficiency
- inability to breakdown elastase
- too much elastase in the blood
- elastase breakdown elastin
- without elastin, the lungs looses its elasticity
what is the environmental factors of emphysema and how it cause emphysema ?
tobaccoo smoke and air pollution
- triggers inflammatory response
- increase the number of neutrophils, microphases, elastase and protease
- neutrophils produces elastase
what is the role of elastin?
it allows the lungs to expand and recoil to allow the air in the lungs to be expelled
what happen when there is a breakdown of elastic tissue and collagen in the lungs ?
- air cannot be expelled easily and is trapped in the lungs
- there will be inflammation of bronchioles
- in smoke induced emphysema, the increased mucus secretion and inflammation in bronchioles will decrease airway clearance ability