FD in PULMONOLOGY Flashcards
Boyles law ?
air( gas) pressure is inversely proportional to air volume
P1P2= V2V2
Primary principle of ventilation
Air moves down a pressure gradient (from an area of high pressure to low pressure)
What is the atmospheric pressure and intra pulmonary pressure
760mmHg
Muscles used for breathing
Intercostal muscles(main) Diaphragm(main ) Accessory muscles - sternocloidomastoid muscle , Scalene muscle
What happens in inspiration
The volume of the lungs increase due to the constriction of the 2 muscles ( diaphragm and intercostal muscles )
During inspiration , the diaphragm contracts and moves down and it will allow the intrapulmonary volume to increase which will cause the intra pulmonary pressure to decrease (759mmHg, difference is -1mmHg) below the atmospheric pressure so because of the rule of gases , the air will flow into the lungs down its pressure gradient
What happens in expiration ?
The diaphragm and the intercostal muscles relaxes and the diaphragm will move back up to its original place which will cause the intra pulmonary volume to decrease and intra pulmonary pressure to increase (761mmHg) difference is (+1)
Following the rule of gases So gases ( air) will move outside the lungs into the air outside down the pressure gradient
4 Lara nasal sinuses are
Frontal
Sphenoid
Ethmoid
Maxillary
methods of functional diagnostics of pulmonary diseases
Spirometry Bronchial provocation test Pneumotachography Peak flow metry Flow volume curve of forced expiration Body plethysmography
- In spirometry FVC - is
The total amount of air that can forcibly be blown out after full inspiration
Purpose of PFT
1) Diagnosis of symptomatic disease
2) used to screen for early asymptomatic disease in high risk people e.g people with prolonged exposure to amiodarone
3) Used in people with occupational exposure or environmental exposure
4) To prognose known disease
5) Used to estimate surgical risk
6) Used to monitor response to treatment
Obstructive lung diseases are
Chronic bronchitis Bronchial asthma Cystic fibrosis Bronchiectasis Emphysema
Types of PFT
Spirometry Lung volumes DLCo Peak flow metry Arterial blood gas Exercise oximetry Maximum inspiratory and expiration pressures
Tidal volume is ?
the amount of air that moves in or out of the lungs with each respiratory cycle.
Volume of air inspired and expired during quiet normal breathing
Expiratory reserve volume
Inspiratory reserve volume
Inspiratory reserve volume – volume which can be inhaled additionally
after normal inspiration
3. Expiratory reserve volume – volume which can be exhaled additionally
after normal expiration
Residual volume –
volume remaining in the lungs after maximal expiration
Lung volumes are ?
Tidal volume
Inspiratory reserve volume
Expiratory reserve volume
Residual volume