Lecture 4 Flashcards
Some most important disease that interfere with movement of air is called
Chronic obstructive pulmonary disease
What 3 conditions make up the COPD circle
Chronic bronchitis
Asthma
Emphysema
What is asthma
Reduction in airway diameter due to inflammation or contraction of smooth muscle
What is chronic bronchitis
Secretions blocking the airway
What is emphysema
Collapse of airways due to disruption of parenchyma
Intrapleural pressure is split into two sections
Static component
Dynamic component
What does the static component do
Holds the lungs open
What does the dynamic component do
Moves air in and out
Airflow happens in what direction
High to low
Where and when is the pressure the same when we breathe
When we pause to exhale or inhale
The pressure is the same at the lips to the alveoli
What does recoil of the lungs resist and assist
Resists inspiration
Assists expiration
Laminar flow has what pressure gradient
Small
Turbulent flow has what type of pressure
Large
In regards to radius what does it do to resistance and velocity
Resistance increases 16th
Velocity reduced 16th
In a tube where is the most air (new) travelling through
The middle of the tube
What sort of low volume are we talking about in chest trauma
50Hz
What do we need to measure airway resistance
Driving pressure and the airflow of the tube
Airways resistance is said to only be
Dynamic
What instrument is used to test airway resistance
Pneumotachograph
How do we measure intrapleural pressure
Insertion of a small balloon in oesophagus
How do we work out alveoli pressure
Subtracting changes in recoil pressure from changes in intrapleural pressure
What is a whole body plethysmograph
Airtight box where a patient pants against a closed shutter or Pneumotachograph while pressure change in the mouth and box
Distribution of airway resistance in an Open mouth
Mouth to trachea
Trachea to alveolar duct
Mouth to trachea 35-40%
Trachea to alveolar duct 60-65%
Distribution of airway resistance in nasal breathing
Mouth to trachea
Trache to alveolar duct
Mouth to trachea 40-50%
Trachea to alveolar duct 50-60%
Of the amount residing below the larynx how much resides in the trachea and bronchi
80%
What cells release cytokines in response to allergens
NKT cells
What do the cytokines do when released
Trigger inflammation and this causes the air passage to become inflamed and mucus filled
What does NANC mean
Non adrenergenic non cholinergic nerve
What does VIP mean
Vasoactive intestinal peptide
What does RAR mean
Rapidly adapting pulmonary sensory receptor
What does PSR mean
Slowly adapting
Name 7 factors of the bronchomotor tone
- Parasympathetic innervation (contracts)
- Circulating catecholamines
- Autonomic nerve supply (relaxes)
- Mast cell degranulation
- Neutrophils and eosinophils
- RAR contracts an PSR relaxes
- CO2 directly relaxes muscle
Inflammation during asthma does what
Irritates the lining of bronchial tubes so tey become swollen and inflamed an excess mucus makes breathing difficult
Bronchoconstriction of asthma does what
Bands of muscle surround the bronchial tubes contract causing the airway to narrow
What are the 2 stages of asthma
Immediate phase - spasm of bronchial muscle
Late phase - acute inflammation reaction
Treatment of asthma
Early stage - relax smooth muscle eg xanthines
Late stage - reduce inflammation eg glucocorticoids
What is bronchitis
Excessive production of lung mucus
What is radial traction
Parenchyma forms a
Scaffolding aroun airways
If parenchyma was rigid what would doubling linear dimensions increase too
Increase volume 8x
Increase conductance 2 power 4
What happens when low lung volume appears
Airways collapse and radial support disappears and airway pressure increases
In emphysema is radial traction is lost what happens to the alveoli
They collapse
What is the best measurement of obstructive diseases
Flow / volume curve
What % is work of breathing at rest
What is work
Intrapleural pressure X change in volume
Work of breathing is made up of
Elastic resistance of tissues
Airflow resistance
Some work done by inspiration is recovered by what
Elastic recoil
What is total work of breathing
Work done against recoil and work to produce airflow
What 4 categories are clinical presentation
At risk
Symptomatic
Exacerbations
Respiratory failure
