Physiology Flashcards
1
Q
Define vital capacity
A
- Volume of air that can be expelled from the lungs after maximal inspiration
- Slow/relaxed maneouvre
2
Q
Define forced vital capacity
A
- Volume of air that can be forcibly expelled from the lungs from maximal inspiration
3
Q
Define Forced expiratory volume (FEV1)
A
Volume of air expelled from lungs in 1st second following maximal inspiration
4
Q
Define FEV1/FVC
A
Volume of air expelled in first second as a percentage of the total volume of air exhaled
5
Q
Draw the volume time graphs for obstructuve and restrictive disease against normal
A
6
Q
Draw a lung volume graph (6)
A
7
Q
4 causes of low paO2
A
- Hypoventilation
- Diffusion impairement
- Shunt
- V/Q mismatch
8
Q
Causes of respiratory acidosis
A
- Hypoventilation - eg neuromuscular diseases
- Alveolar hypoventilation - eg COPD
9
Q
What is the A-a gradient?
A
Alveolar to arterial gradient
10
Q
Equation for A-a gradient
A
PAO2 (aleveolar) =
PIO2 (approx 20kPa) minus (PaCO2/0.8)
11
Q
Normal A-a gradient
A
Less than 2kPa in young healthy people
Less than 4kPa in elderly
More than 4 suggests lung pathology
12
Q
A
