Central control of respiration Flashcards
What is breathing?
an automatic, rhythmic process
What is the basic respiratory rhythm generated?
centres in the medulla
What can alter the involuntary mechanism of breathing?
- hyperventilation
- breath holding
If there is a severance above the level of the medulla (between the medulla & pons) what happens?
the individual maintains a basic rhythmic pattern of breathing
If there is a severance below the level of the medulla (between the medulla & pons) what happens?
the breathing pattern is lost
What is DRG (dorsal respiratory group)?
group of neurones
- primary link to inspiration - nerve outputs down to:
- phrenic nerve (to diaphragm)
- spinal nerves (to inter-costal muscles associated with inspiration)
(associated with quiet breathing)
What is VRG (ventral respiratory group)?
group of neurones
- links to inspiration & expiratory
- linked to VRG is a small region of neurones known as the “pre-botzinger complex” - which is where the basic pattern of breathing is generated from. This sends signals to the DRG, to control inspiration.
- by moderating this pattern, you can control respiration rate
What is VRG (ventral respiratory group) associated to?
mainly associated with forced inspiration & forced expiration
What are the 2 centres in the Pons region of the brain?
- pneumotaxic center
- apeustic center
Where is the basic pattern of breathing generated from?
pre-botzinger complex
What is in the pneumotaxic centre?
increase the rate by shortening inspirations.
- inhibitory effect on inspiration centre
What is in the apenustic centre?
increases the depth and reduces the rate by prolonging inspirations.
- stimulates inspiratory centre
What is the Hering-Breuer reflex?
stretch receptors in the lung send signals back to the medulla to limit inspiration & prevent over-inflation of the lungs.
What is the benefit of the Hering-Breuer reflex?
prevents over-inflation of the lungs
Through which nerve does the Hering-Breur reflex tell the inspiration centre to stop inspiration?
vagus nerve
What are the central chemoreceptors?
monitor conditions in the cerbro-spinal fluid. Sending CO2 & pH. indirect response to a rise in CO2 - stimulation leads to an increase in ventilation.
Where are the peripheral chemoreceptors?
located in the carotid body & aortic arch
What do peripheral chemoreceptors respond to?
- increase in CO2
- decrease in pH
- decrease in O2
What does stimulation of the central & peripheral chemoreceptors lead to?
stimulation leads to an increase in ventilation
