Distribution of inspired gases and gas transfer (self directed) Flashcards
How does airway resistance changed in supine position compared to upright position
Airway resistance is increases in supine compared to upright position
What is the compliance like in high pressures and why
At high pressure, the lung is stiffer, hence compliance is lower (eg like a balloon)
Which part of the lung are more compliant and what does this mean
Lung bases are more compliant (>volume) than the apex so there is better ventilation
What is decreased compliance because of
pulmonary fibrosis and alveolar oedema
What is increased compliance due to
Normal ageing of lung
What happens to lung compliance as you age, and why
Compliance increases with age due to a loss in elastic recoil
What does a loss in elastic recoil prevent
complete exhalation
What is characteristic of emphysema and what does this prevent
increased compliance and decreased elastic recoil
-prevents complete exhalation
What is characteristic of pulmonary fibrosis and what does this mean
Decreased compliance
-Extra work required for ventilation
What does oedema fluid in the interstitial space or fibrosis of the lung mean
Increased diffusion resistance which means there’s an interference with normal gas exchange
Out of oxygen and Co2, which moves faster through gas and why
O2 moves faster because larger molecules diffuse more slowly
Out of O2 and Co2, which moves faster in liquid and why
Co2 diffuses faster because it is more soluble than O2
How is gas transfer and respiration controlled
Neural regulation
Chemical regulation
Where is voluntary breathing controlled
Cerebral cortex
Where is involuntary breathing controlled
Pons
Medulla
