Control of respiration Flashcards
What type of breathing is sub-conscious and occurs at rest?
Quiet breathing
What is deep breathing?
Sub-conscious or deliberate and increases amplitude of ventilatory movements
What is forced breathing?
Deliberate, increases amplitude of ventilatory movements to limit of thoracic volume change
What are the short term challenges with the respiratory system?
Maintain oxygen supply and ensure CO2 removal from metabolising tissues
What are the long term challenges with the respiratory system?
Avoid or repay oxygen debts and ensure CO2 removal from blood
What is the short and long term challenge with the respiratory system?
Maintain blood pH
What changes are made to allow different gas supplies?
Frequency of ventilation
Depth of ventilation
Airway resistance
Amount of gas carried in blood
Rate of blood circulation
Passage of blood through tissues
How does the brain affect the respiratory system?
Control sub-conscious and conscious ventilation
Where is ventilation exerted?
Through nerves to diaphragm and intercostal muscles
What are the regulating factors of ventilation?
Blood PCO2, PO2 and H+
Where are the pons and medulla located?
Brainstem
Where do the pons and medulla receive information from?
Chemoreceptors, stretch receptors and cerebral cortex
Where does the pons send signals?
To the medulla
Where do signals go from the medulla?
Rhythmically to the spinal cord through inspiratory neurons
Where do signals go from the spinal cord?
To the diaphragm through cervical nerve 4
What is cervical nerve 4?
Phrenic nerve
What are the 4 sections of the brainstem?
Above pons
Mid-pons
Between pons and medulla
Below medulla
What occurs in the above pons?
Involuntary respiration with lower rhythmic frequency
What occurs in the mid-pons?
Lower frequency, deeper inspiration
What occurs between the pons and medulla?
Gasping or irregular inspiration
What occurs below the medulla?
No voluntary respiration
Role of cortex
Controls voluntary respiration
Role of pneumotaxic centre (PC)
Terminates and limits inspiration
What prevents inspiratory neurons from being turned off?
Apneustic centre (AC)
What is in the medulla?
Inspiratory and expiratory control centres
Role of ventral respiratory group/column
Regulates amplitude and frequency of ventilation
Role of dorsal respiratory group (DRG)
Transfers inspiratory signals to diaphragm
What are the central chemoreceptors?
Medullary respiratory centres
What are the peripheral chemoreceptors?
Aortic and carotid bodies
Where are carotid bodies located?
On each side near carotid artery
Role of carotid bodies
Monitor H+ and O2
Where are aortic bodies located?
Near the aortic arch
Role of aortic bodies
Monitor O2
Where do aortic and carotid bodies’ afferent nerves transfer signals?
Medulla and pons through vagus and glossopharyngeal nerves
What happens when arterial PO2 is low?
Peripheral chemoreceptors detect the change and increase ventilation
How are PCO2 levels detected?
Central chemoreceptors monitoring pH in the ECF
What happens when inspired CO2 increases?
Rate and depth of ventilation increases
When is ventilation maximum?
At 6.6% CO2
What happens if CO2 becomes higher than 6.6%?
Acidosis occurs because CO2 can’t be removed by hyperventilation
