RESP 103&105 COPD and Pleurisy Flashcards
What is the pressure of air at sea level?
760mmHg
Where does the trachea bifurcate?
At the carina about TIV/V
What cells line the respiratory tract?
Ciliated columnar epithelial cells
What is contained within mucus to help fight infection?
anti-trypsins, lysozyme and immunoglobulin A
What cells line the wall of the alveoli and alveolar ducts?
Type 1 and 2 pneumocytes
Which cells in the alveoli secrete surfactant
Type 2 pneumocytes
What is the function of surfactant?
to decrease surface tension and prevent alveolar collapse
What is the tidal volume of lungs?
The volume of air drawn into and out of the lungs during normal breathing
What is the vital capacity of lungs?
The maximum tidal volume - breathing in and out as much as possible
What is the difference between resting and maximum expiratory/inspiratory volume?
expiratory reserve volume
inspiratory reserve volume
What is the volume of the lungs after a maximum inspiration called?
Total lung capacity
What is the volume in the lungs called after maximum expiration?
residual volume
What is the functional residual capacity?
The volume of air left in the lungs a the end of a normal breath
What is functional residual capacity determined by?
Outward elastic recoil of the chest wall and inward elastic recoil of the lungs
What is the normal intrapleural pressure?
-0.2 to -0.5 kPA
What happens to the intrapleural pressure during inspiration?
It becomes more negative = lung and alveolar expansion
What happens to the intrapleural pressure during expiration?
It rises but remains negative
What is Laplace’s law and why is it relevant in the lungs?
Describes how the pressure in a bubble is proportional to the surface tension and radius
In alveoli, producing surfactant reduces the surface tension as otherwise the high pressure inside the alveoli would suck fluid in and cause collapse
What is Darcy’s Law and what does it describe?
Describes flow through airways
alveolar pressure - mouth pressure / resistance to airflow
What does Pouseilles law describe?
That resistance is determined by radius and whether flow is laminar or turbulent
What is Daltons Law?
Total pressure = the sum of partial pressures of constituents
What is Ficks Law?
The rate of diffusion across a membrane is proportional to: concentration difference, membrane SA, diffusion constant and inversely proportional to thickness
What are the 4 stages in transport of oxygen to tissues?
Ventilation of alveoli by convection
Diffusion of 02 across alveolar membrane
Oxygenated blood is pumped around by convection
02 diffuses from capilliaries to tissues
Where are chemoreceptors found that control breathing?
medulla, carotic and aortic bodies
What do the chemoreceptors detect (lung work)?
PaCo2 - maintained at 40mmHg
Pa02 and pH
What is COPD?`
A disease causingn airflow obstruction
What are symptoms of COPD?
cough, sputum, wheeze and breathlessness
What is emphysema?
Destruction of lung tissues after terminal bronchioles resulting in floppy airways
What deficiency is a risk factor for emphysema?
alpha-1 antitrypsin deficiency
What is chronic bronchitis?
inflammatory process in the wall of the bronchioles with excess mucus production from hypetrophied flands
What is the diagnostic criteria for chronic bronchitis?
Cough, productive of purulent sputum >3months of at least 2 consecutive years
What is hypoxaemia?
<8.0kPa 02 in arterial blood
How would you describe “pink puffer”?
Barrel chests with dyspnoea, use of accessory muscles and weight loss
Why do patients become “pink puffers”?
Low pa02 with normal/low PaCO2
Low paO2 drives respiration and high resp effort maintain paC02
Describe “blue bloaters”
Less breathless, cyanosed, flapping tremor, oedema and high JVP
Why do blue bloaters become oedematous and have a high JVP?
due to right sided heart failure as a result of pulmonary hypertension
Why do patients become blue bloaters?
They have a low PaO2 and high PaCO2 as they don’t have enough effort to maintain paCO2
What are some short acting beta agonists?
salbutamol and terbutaline
What are some long acting beta agonists?
salmeterol and formoterol
Name two muscarinic antagonists and what they are used for
Ipratropium and tiotropium reduce effect of bronchoconstriction in COPD
Name a mucolytic and its use
Carbocisteine and decreases acute exacerbation of COPD and need for abx
What is the pleura?
mesothelium derived from mesoderm
What produces the serous fluid contained within the pleural space?
mesothelial cells
What law describes the maintenance of fluid movement in and out of the pleural space?
Starlings hypothesis
What is pneumothorax?
Air in the pleural space
What can pneumothorax be due to?
rupture of sub pleural blebs,as a result of respiratory disease or iatrogenic
What is a transudate?
A low protein, clear fluid not associaed with infection but with congestive heart, liver or renal failure
What is an exudate?
A high protein, milky coloured fluid full of inflammatory cells usually associated with disease of pleura or lung
