Respiratory 5 Flashcards
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
Increasing PaCO2 causes an X in minute ventilation.
deranged
- Increasing PaCO2 causes an increase in minute ventilation.
- This is mediated by peripheral chemoreceptors over the timescale of seconds, and by central chemoreceptors over minutes.
o Peripheral chemoreceptors are the carotid glomus cells, which sense PaCO2 as well as PaO2, pH, temperature and blood pressure
o Central chemoreceptor areas are found in multiple areas of the brain, but are generally said to concentrate in the ventral medulla - The relationship between PaCO2 is fairly linear in the range of 45-80 mmHg; the rate of minute volume increases by 2-5L/min per every 1mm Hg of CO2 increase.
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
how does PaCO2 change alveolar ventilation
deranged
- Increasing PaCO2 causes an increase in minute ventilation.
- This is mediated by peripheral chemoreceptors over the timescale of seconds, and by central chemoreceptors over minutes.
o Peripheral chemoreceptors are the carotid glomus cells, which sense PaCO2 as well as PaO2, pH, temperature and blood pressure
o Central chemoreceptor areas are found in multiple areas of the brain, but are generally said to concentrate in the ventral medulla - The relationship between PaCO2 is fairly linear in the range of 45-80 mmHg; the rate of minute volume increases by 2-5L/min per every 1mm Hg of CO2 increase.
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
o Peripheral chemoreceptors are the X, which sense PaCO2 as well as PaO2, pH, temperature and blood pressure
deranged
- Increasing PaCO2 causes an increase in minute ventilation.
- This is mediated by peripheral chemoreceptors over the timescale of seconds, and by central chemoreceptors over minutes.
o Peripheral chemoreceptors are the carotid glomus cells, which sense PaCO2 as well as PaO2, pH, temperature and blood pressure
o Central chemoreceptor areas are found in multiple areas of the brain, but are generally said to concentrate in the ventral medulla - The relationship between PaCO2 is fairly linear in the range of 45-80 mmHg; the rate of minute volume increases by 2-5L/min per every 1mm Hg of CO2 increase.
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
o Peripheral chemoreceptors are the carotid glomus cells, which sense X
deranged
- Increasing PaCO2 causes an increase in minute ventilation.
- This is mediated by peripheral chemoreceptors over the timescale of seconds, and by central chemoreceptors over minutes.
o Peripheral chemoreceptors are the carotid glomus cells, which sense PaCO2 as well as PaO2, pH, temperature and blood pressure
o Central chemoreceptor areas are found in multiple areas of the brain, but are generally said to concentrate in the ventral medulla - The relationship between PaCO2 is fairly linear in the range of 45-80 mmHg; the rate of minute volume increases by 2-5L/min per every 1mm Hg of CO2 increase.
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
Central chemoreceptor areas are found in multiple areas of the brain, but are generally said to concentrate in the X
deranged
- Increasing PaCO2 causes an increase in minute ventilation.
- This is mediated by peripheral chemoreceptors over the timescale of seconds, and by central chemoreceptors over minutes.
o Peripheral chemoreceptors are the carotid glomus cells, which sense PaCO2 as well as PaO2, pH, temperature and blood pressure
o Central chemoreceptor areas are found in multiple areas of the brain, but are generally said to concentrate in the ventral medulla - The relationship between PaCO2 is fairly linear in the range of 45-80 mmHg; the rate of minute volume increases by 2-5L/min per every 1mm Hg of CO2 increase.
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
- The relationship between PaCO2 is fairly X in the range of X; the rate of minute volume increases by X
deranged
The CO2/ventilation response curve is shifted to the left by metabolic acidosis and hypoxia
Sleep, sedation, anaesthesia and opiates shift the curve to the right and decrease the slope of the curve (i.e. the increase in minute ventilation is reduced per unit rise of CO2)
Age decreases the ventilatory response to CO2
A high level of physical fitness also diminishes hypercapnic respiratory drive
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
The CO2/ventilation response curve is shifted to the x by metabolic acidosis and hypoxia
deranged
The CO2/ventilation response curve is shifted to the left by metabolic acidosis and hypoxia
Sleep, sedation, anaesthesia and opiates shift the curve to the right and decrease the slope of the curve (i.e. the increase in minute ventilation is reduced per unit rise of CO2)
Age decreases the ventilatory response to CO2
A high level of physical fitness also diminishes hypercapnic respiratory drive
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
Sleep, sedation, anaesthesia and opiates shift the curve to the x and x the slope of the curve (i.e. the xin minute ventilation is reduced per unit rise of CO2)
deranged
The CO2/ventilation response curve is shifted to the left by metabolic acidosis and hypoxia
Sleep, sedation, anaesthesia and opiates shift the curve to the right and decrease the slope of the curve (i.e. the increase in minute ventilation is reduced per unit rise of CO2)
Age decreases the ventilatory response to CO2
A high level of physical fitness also diminishes hypercapnic respiratory drive
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
Age x the ventilatory response to CO2
deranged
The CO2/ventilation response curve is shifted to the left by metabolic acidosis and hypoxia
Sleep, sedation, anaesthesia and opiates shift the curve to the right and decrease the slope of the curve (i.e. the increase in minute ventilation is reduced per unit rise of CO2)
Age decreases the ventilatory response to CO2
A high level of physical fitness also diminishes hypercapnic respiratory drive
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
A high level of physical fitness also x hypercapnic respiratory drive
deranged
The CO2/ventilation response curve is shifted to the left by metabolic acidosis and hypoxia
Sleep, sedation, anaesthesia and opiates shift the curve to the right and decrease the slope of the curve (i.e. the increase in minute ventilation is reduced per unit rise of CO2)
Age decreases the ventilatory response to CO2
A high level of physical fitness also diminishes hypercapnic respiratory drive
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
The response to raised PaCO2 is X; about X% of the maximum minute volume change is achieved over X
deranged
The response to raised PaCO2 is rapid; about 75% of the maximum minute volume change is achieved over minutes
At a stable metabolic rate and with minimal inspired CO2 the relationship between minute volume and PaCO2 is described by a hyperbolic curve.
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
At a stable metabolic rate and with minimal inspired CO2 the relationship between minute volume and PaCO2 is described by a x
deranged
The response to raised PaCO2 is rapid; about 75% of the maximum minute volume change is achieved over minutes
At a stable metabolic rate and with minimal inspired CO2 the relationship between minute volume and PaCO2 is described by a hyperbolic curve.
Describe the role of carbon dioxide in the control of alveolar ventilation
2019 march Q16
examiner comment
deranged
Better answers considered the role of CO2 in the control of alveolar ventilation in terms of sensors, central processing and effectors - with an emphasis on sensors. Features of central and peripheral chemoreceptors should have been described in detail. The PCO2/ventilation response curve is best described using a graph, with key features of the curve identified (including gradient and axes). Various factors affecting the gradient of this curve and how CO2 affects the response to hypoxic drive should be described.
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Airway function and structure
deranged
increased airway reactivity
Decreased ciliary number and activity
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Airway function and structure
Increased airway reactivity
Decreased ciliary number and activity
what is effect of these changes?
deranged
Higher risk of bronchospasm
Bronchospasm requires a lesser stimulus
Clearance of secretions is impaired
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Structural properties of the chest wall:
deranged
Calcification of costal ligaments
Thoracic vertebral height loss
Kyphosis
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Structural properties of the chest wall:
Calcification of costal ligaments
Thoracic vertebral height loss
Kyphosis
what is effect of these changes?
deranged
Decreased chest wall compliance
Higher residual volume (RV)
Higher FRC
Lower vital capacity (VC)
Unchanged total lung capacity (TLC)
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Function of respiratory muscles:
deranged
Decreased total muscle mass
Decreased muscle strength
Decreased proportion of fast-twitch fibres
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Function of respiratory muscles:
Decreased total muscle mass
Decreased muscle strength
Decreased proportion of fast-twitch fibres
what is effect of these changes?
deranged
Decreased MIP (maximum inspiratory pressure)
Decreased FEV1
Decreased maximum minute ventilation
Fatigue develops more rapidly
Exercise capacity is decreased
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Structure of the lungs
deranged
“Senile emphysema”- hyperinflation
Degeneration of elastic fibres
Reduction in supporting tissue around small airways
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Structure of the lungs
“Senile emphysema”- hyperinflation
Degeneration of elastic fibres
Reduction in supporting tissue around small airways
what is effect of these changes?
deranged
Increased lung compliance
Decreased elastic recoil
Decreased diaphragmatic excursion
Increased dead space ventilation
Increased closing volume due to premature small airway closure, increasing the risk of gas trapping
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Gas exchange
deranged
Increased alveolar–capillary membrane thickness
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Gas exchange
Increased alveolar–capillary membrane thickness
what is effect of these changes?
deranged
Decline in DLCO
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Control of ventilation
deranged
Decrease in efferent neural output to respiratory muscles
Decline in DLCO
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Control of ventilation
Decrease in efferent neural output to respiratory muscles
Decline in DLCO
what is effect of these changes?
deranged
50% reduction in response to hypoxia
40% reduction in response to hypercarbia
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Immunological changes
deranged
Increased immunoglobulin content
Decreased alveolar macrophage population
Describe the effects of ageing on the respiratory system.
2019 march Q19
Age-related changes
Immunological changes
Increased immunoglobulin content
Decreased alveolar macrophage population
what is effect of these changes?
deranged
Increased susceptibility to bronchospasm
Increased susceptibility to infection
Slower recovery from infection
Describe the effects of ageing on the respiratory system.
2019 march Q19
examiner comments
Answers should have included the effects of ageing on the efficiency of gas exchange, how the expected PaO2 changes with age, and its causation. Anatomical changes should have been included as should changes in lung volumes, particularly the significance of an increased closing volume. Marks were not awarded for the effects of disease states.
