Primary FRCA Course Resp Physiology Exam Prep Questions Flashcards
The functional residual capacity
is increased in the obese
False. Common causes of reduced FRC include general anaesthesia, abdominal masses (inc pregnancy and obesity), supine position and in children or the elderly.
The functional residual capacity
is approximately 10 per cent higher in men than in women
True
The functional residual capacity
falls with general anaesthesia
True. Common causes of reduced FRC include general anaesthesia, abdominal masses (inc pregnancy and obesity), supine position and in children or the elderly.
The functional residual capacity
increases on changing from the supine to the standing position
True. Common causes of reduced FRC include general anaesthesia, abdominal masses (inc pregnancy and obesity), supine position and in children or the elderly.
The functional residual capacity
falls with increasing age
False. Common causes of reduced FRC include general anaesthesia, abdominal masses (inc pregnancy and obesity), supine position and in children or the elderly.
Vital capacity
is the volume of air expired from full inspiration to full expiration
True
Vital capacity
increases gradually with age in adults
False. VC decreases with age
Vital capacity
is greater in men than in women of similar age and height
True
Vital capacity
is equal to the sum of the inspiratory and expiratory reserve volumes
False. This would not include tidal volume
Vital capacity
may be measured by spirometry
True
Closing capacity
is larger than functional reserve capacity
False. When closing capacity is greater than FRC, small airways closure occurs during normal tidal breathing. This can occur, but is by no means normally the case
Closing capacity
may be determined by single breath N2 curve following a deep breath of oxygen
False. This method determines closing volume. Residual volumes would need to be added to calculate closing capacity. Fowler’s method (multiple breath N2 curve) can do this.
Closing capacity
is high in young children and decreases progressively with advancing age
False. It is low in infancy and increases with age
Closing capacity
if high, may be responsible for arterial hypoxaemia
True. Due to shunt caused by small airways closure.
Closing capacity
is unaffected by bronchomotor tone
False.
Closing volume
increases with age
True
Closing volume
decreases during anaesthesia
True. This offers a degree of protection against the drop in FRC seen. Once FRC reaches Closing Capacity (the sum of Closing Volume and Residual Volume) small airways closure begins
Closing volume
is increased in the upright position
False. It increases in the supine position
Closing volume
is decreased in obesity
False. It increases in obesity, compounding the problem of reduced FRC
Closing volume
can be measured by a single breath nitrogen technique
True. Unlike closing capacity.
FRC can be measured using
Helium wash-in
True. The three methods of measuring FRC are plethysmography, nitrogen wash-out and helium wash-in. Spirometry will measure all lung volumes except FRC, residual volume and TLC. Intra-oesophageal balloons are used to measure intra-pleural pressure.
FRC can be measured using
Nitrogen wash-out
True. The three methods of measuring FRC are plethysmography, nitrogen wash-out and helium wash-in. Spirometry will measure all lung volumes except FRC, residual volume and TLC. Intra-oesophageal balloons are used to measure intra-pleural pressure.
FRC can be measured using
Body plethysmography
True. The three methods of measuring FRC are plethysmography, nitrogen wash-out and helium wash-in. Spirometry will measure all lung volumes except FRC, residual volume and TLC. Intra-oesophageal balloons are used to measure intra-pleural pressure.
FRC can be measured using
Spirometry
False. The three methods of measuring FRC are plethysmography, nitrogen wash-out and helium wash-in. Spirometry will measure all lung volumes except FRC, residual volume and TLC. Intra-oesophageal balloons are used to measure intra-pleural pressure.
FRC can be measured using
Intra-oesophageal balloon
False. The three methods of measuring FRC are plethysmography, nitrogen wash-out and helium wash-in. Spirometry will measure all lung volumes except FRC, residual volume and TLC. Intra-oesophageal balloons are used to measure intra-pleural pressure.
The following are required to calculate the pulmonary shunt fraction (Qs/QT)
FiO2
True. This appears in the alveolar gas equation.
To calculate the end capillary oxygen content, PAO2 is assumed to be equal to, and substituted into, the oxygen content equation in place of PcO2. PAO2 is calculated using the alvealor gas equation.
The following are required to calculate the pulmonary shunt fraction (Qs/QT)
Cardiac output
False. Cardiac output (QT) is part of the Shunt Fraction. If you were calculating QS alone you would need to know QT
The following are required to calculate the pulmonary shunt fraction (Qs/QT)
PaCO2
True. This is taken as being equal to PACO2 (which appears in the alveolar gas equation).
To calculate the end capillary oxygen content, PAO2 is assumed to be equal to, and substituted into, the oxygen content equation in place of PcO2. PAO2 is calculated using the alvealor gas equation.
The following are required to calculate the pulmonary shunt fraction (Qs/QT)
arterial O2 content
True. This appears directly in the shunt equation
The following are required to calculate the pulmonary shunt fraction (Qs/QT)
mixed venous O2 content
True. This appears directly in the shunt equation
Surfactant
is a mucopolypeptide
False. It is a phoshpholipid
Surfactant
causes a decrease in surface tension
True.
Surfactant
equilibrates surface tension for different sized alveoli
False. It equilibrates alveolar pressure by differentially reducing surface tension more in small alveoli.
Surfactant
causes an increase in compliance
True.
Surfactant
production is reduced after a prolonged reduction in pulmonary blood flow
True. It it synthesised from free fatty acids, extracted from the blood.
Pulmonary Surfactant
is a mixture of phospholipids and proteins
True.
Pulmonary Surfactant
causes an increase in chest wall compliance
False. It does not affect the chest wall
Pulmonary Surfactant
prevents transudation of fluid from the blood into the alveoli
True. High surfance tension would tend to draw fluid into the alveoli
Pulmonary Surfactant
deficiencies in babies born to diabetic mothers is due to fetal hyperinsulinism
True.
Pulmonary Surfactant
concentration per unit area is directly proportional to surface tension
False. It is indirectly proportional
Alveolar - arterial oxygen difference (A-a DO2
is normally 2-3 kPa while breathing room air
True
Alveolar - arterial oxygen difference (A-a DO2
is increased under anaesthesia due to increased V/Q mismatch
True. The major causes of and increased A-a difference are Shunt / low V/Q ratio and diffusion defects.
Alveolar - arterial oxygen difference (A-a DO2
is decreased in one lung ventilation
False. Due to large shunt created. The major causes of and increased A-a difference are Shunt / low V/Q ratio and diffusion defects.
Alveolar - arterial oxygen difference (A-a DO2
is increased in the presence of right to left intracardiac shunts
True. These represent true shunts. The major causes of and increased A-a difference are Shunt / low V/Q ratio and diffusion defects.
Alveolar - arterial oxygen difference (A-a DO2
is decreased in severe exercise
False. The A-a difference widens at high intensity levels of exercise. The major causes of and increased A-a difference are Shunt / low V/Q ratio and diffusion defects.
PaCO2-EtCO2 gradient
is up to 0.7 kPa in patients wihout significant disease
True.
PaCO2-EtCO2 gradient
increases in venous air embolism
True. The PaCO2-EtCO2 gradient increases with any cause of increased dead space.
PaCO2-EtCO2 gradient
is greater in high frequency ventilation
True.
PaCO2-EtCO2 gradient
is greater in high V/Q areas of the lungs
True. The PaCO2-EtCO2 gradient increases with any cause of increased dead space.
PaCO2-EtCO2 gradient
is greater in patients with poor cardiac output
True. The PaCO2-EtCO2 gradient increases with any cause of increased dead space.
When the ventilation/perfusion ratio of a lung unit increases
the alveolar PO2 rises
True. Alveolar PO2 will tend towards inspired PO2 in areas of dead space
When the ventilation/perfusion ratio of a lung unit increases
the alveolar CO2 rises
False. Alveolar CO2 falls in areas of dead space
When the ventilation/perfusion ratio of a lung unit increases
end capillary PO2 increases
True. Due to the increased alveolar PO2
When the ventilation/perfusion ratio of a lung unit increases
arterial PO2 increases
True. Contrary to intuition, this is true, although the cause of dead space in one lung unit may cause shunt in another with the net effect being hypoxia, such as seen after a PE
When the ventilation/perfusion ratio of a lung unit increases
hypoxic pulmonary vasoconstriction will compensate for any change in gas exchange
False. It will provide a degree of compensation only
The distribution of ventilation of an upright subject is related to
regional airways diameters
True.
At normal lung volumes, the intrapleural pressure is greater (less negative) in the dependent part of the lung (this greater pressure provides support to the weight of lung suspended above it). This gareter pressure results in the lung being at lower volume in the dependent parts. Although lung volume is lower in the non-dependent parts, ventilation is greater as it sits on the steep part of the compliance curve.
The distribution of ventilation of an upright subject is related to
regional differences in compliance
True.
At normal lung volumes, the intrapleural pressure is greater (less negative) in the dependent part of the lung (this greater pressure provides support to the weight of lung suspended above it). This gareter pressure results in the lung being at lower volume in the dependent parts. Although lung volume is lower in the non-dependent parts, ventilation is greater as it sits on the steep part of the compliance curve.
The distribution of ventilation of an upright subject is related to
inspired oxygen concentration
False. This is not related to ventilation.
The distribution of ventilation of an upright subject is related to
gravitational forces on the lung
True.
At normal lung volumes, the intrapleural pressure is greater (less negative) in the dependent part of the lung (this greater pressure provides support to the weight of lung suspended above it). This gareter pressure results in the lung being at lower volume in the dependent parts. Although lung volume is lower in the non-dependent parts, ventilation is greater as it sits on the steep part of the compliance curve.
The distribution of ventilation of an upright subject is related to
intrathoracic pressure
True.
At normal lung volumes, the intrapleural pressure is greater (less negative) in the dependent part of the lung (this greater pressure provides support to the weight of lung suspended above it). This gareter pressure results in the lung being at lower volume in the dependent parts. Although lung volume is lower in the non-dependent parts, ventilation is greater as it sits on the steep part of the compliance curve.
In an awake, healthy individual in the lateral position, the:
dependent lung has less ventilation
False. The dependent (lower) lung will have better ventilation due to falling on the steeper part of the compliance curve.
In an awake, healthy individual in the lateral position, the:
dependent lung has more perfusion
True
In an awake, healthy individual in the lateral position, the:
V/Q ratio is higher in the dependent lung
False. The dependent lung will have a small degree of shunt (low V/Q ratio) whilst the non-dependent lung will have a degree of dead space (high V/Q).
In an awake, healthy individual in the lateral position, the:
PAO2 is higher in the lower lung
False. The degree of shunt will lower PAO2 and raise PACO2.
In an awake, healthy individual in the lateral position, the:
PACO2 is lower in the lower lung
False. The degree of shunt will lower PAO2 and raise PACO2
The following vessels are important in physiological shunt
bronchial veins
True.
The following vessels are important in physiological shunt
thebesian veins
True. drain into the left ventricle
The following vessels are important in physiological shunt
coronary sinus
False. drains into the right atrium
The following vessels are important in physiological shunt
ductus venosus
False.
The following vessels are important in physiological shunt
azygos veins
False. drain into the superior vena cava
An area in the lung with increased V/Q ratio:
represents dead space
True.
An area in the lung with increased V/Q ratio:
represents shunt
False.
An area in the lung with increased V/Q ratio:
is responsible for a decrease in the PAO2 with no change in PACO2
False. PAO2 increases, whilst PACO2 decreases
An area in the lung with increased V/Q ratio:
will cause a degree of hypoxia
False. Dead space per se, is not a cause of hypoxia. It may result in hypoxia if as a result blood is shunted elsewhere with a low V/Q, but this is not a direct result.
An area in the lung with increased V/Q ratio:
may be compensated for by an increased minute ventilation
True. Dead space reduces CO2 excretion, hence the increased PaCO2 - EtCO2 gradient. This may be compensated for by increasing minute ventilation, although the cause of dead space would be better addressed
A pressure-volume curve can be used for measuring
the work of breathing
True. Using the area under the curve
A pressure-volume curve can be used for measuring
functional residual capacity
False. The three methods of measuring FRC are plethysmography, nitrogen wash-out and helium wash-in
A pressure-volume curve can be used for measuring
anatomical dead space
False. Anatomical dead space measured using the Fowler method (nitrogen wash-out)
A pressure-volume curve can be used for measuring
compliance
True.
A pressure-volume curve can be used for measuring
respiratory quotient
False.
Lung compliance
is normally 0.2 L/cm H2O
True.
Lung compliance
is decreased with loss of pulmonary surfactant
True.
Lung compliance
is increased in emphysema
True. Due a reduced elastic recoil that naturally resists alveoalar inflation
Lung compliance
is decreased after induction of general anaesthesia
True. Due to the reduced FRC, the lung sits on the flatter part of the compliance curve
Lung compliance
is different at the apices and bases of lungs
True. Compliance (and hence ventilation) is greater in the dependent part of the lung.
A body plethysmograph can be used to measure
Compliance
True. A body plethysmograph and an oesophageal balloon may be used to measure intrapleural pressure. Measurements of pressure and volume may then be plotted against one another to give pressure: volume compliance loop.
A body plethysmograph can be used to measure
Work of breathing
True. A body plethysmograph and an oesophageal balloon may be used to measure intrapleural pressure. Measurements of pressure and volume may then be plotted against one another to give pressure: volume compliance loop.
A body plethysmograph can be used to measure
Gas exhange
False.
A body plethysmograph can be used to measure
Airway resistance
True. A body plethysmograph and an oesophageal balloon may be used to measure intrapleural pressure. Measurements of pressure and volume may then be plotted against one another to give pressure: volume compliance loop.
A body plethysmograph can be used to measure
FEV1
False.
Concerning lung volumes and capacities
The total volume of both lungs is the vital capacity
False. This is the total lung capacity
Concerning lung volumes and capacities
Closing capacity is the sum of the closing volume and the functional residual capacity
False. Closing capacity is the sum of the closing volume and the residual volume
Concerning lung volumes and capacities
The volume which may be forcibly exhaled in 1 sec is greater than 85 per cent of the vital capacity
False. This is the FEV1, which is approximately 75-85 per cent of the vital capacity
Concerning lung volumes and capacities
The functional residual capacity can be measured with the spirometer
False. FRC, RV and TLC cannot be measured by spirometry.
Concerning lung volumes and capacities
The sum of the inspiratory reserve volume and the expiratory reserve volume is the vital capacity
False. Tidal volume would also be required.
Alveolar
dead space exceeds tidal volume at rest
False. Dead space is in the region of 2 mls/kg, whilst tidal volume is around 5-7 mls/kg
Alveolar
ventilation decreases as tidal volume increases
False.
Alveolar
partial pressure of water vapour exceeds that of carbon dioxide
True. Partial pressure of water vapour in the alveoli is around 6.3 kPa
Alveolar
partial pressure of oxygen falls within an increase in physiological dead space
False.
Alveolar
oxygen uptake exceeds alveolar carbon dioxide output
True
