L20: Control Of Breathing Flashcards
What happens when you transects between the medulla and spinal cord
Ventilation stops
What are the 2 extremes of breathing
Driven by metabolic system
Driven by behavioural system
Which patient present with breathing only due to metabolic system
Locked in syndrome
What is the locked in system a consequence of
Stroke
What happens to a patient in the locked in syndrome
Patient is unable to move voluntarily expect eyes
Regular breathing is driven by metabolic system (involuntary control)
Which patient only breath due to their behavioural system (only breath when aware)
Ondine’s curse
What is Ondine’s curse a result of
Medullary tumour
What does a patient with Ondine’s curse require at night
Mechanical ventilation
What does a patient with Ondine’s curse require mechanical ventilation at night
They are not aware of their breathing when they sleep
What is the metabolic system regulated by
Feedback system of paco2
What is the behavioural system regulated by
Feedforward system of speech, cough etc.
Where is the metabolic system controlled in the brain
Brain stem
Where is the behavioural system controlled in the brain
Cortex
Which information regulated the feedback system of the metabolic system in the brain stem
Chemical
Mechanical
What are 3 phases to breathing
Inspiratory phase (I)
Post inspiratory phase (PI)
E-2 phase
What happens to the diaphragm in the inspiratory phase
Contracts
What happens to the diaphragm in the post expiratory phase
Gradually relaxes
What happens to the diaphragm in the E-2 phase
Silent
At which phase of breathing does the accessory respiratory muscle contract
E-2 phase
What type of control is the metabolic system
Automatic
Where are the automatic respiratory neurones located
Brainstem
What are the automatic neurones called
Dorsal respiratory group
Ventral respiratory group
Pontine respiratory group
Botzinger complex
Which automatic respiratory neurones controls both inspiration and expiration
Ventral respiratory group (VRG)
Pontine respiratory group (PRG)
Which automatic respiratory neurone controls expiration only
Botzinger complex
Which automatic respiratory Neurone controls inspiration only
Dorsal respiratory group (DRG)
Which neurone increases the contraction of the diaphragm
DRG
What happens when we need to increase inspiration
VRG inspiration component is active to it drives to the activity of inspiration accessory muscle
Which neurone is activated to drive expiration
Botzinger complex
What does the botzinger complex do to activate the expiratory accessory muscles
Excites the VRG expiration complex
To stop expiration and ispiration occuring at the same time what occurs
Inhibitory activity
Which neurone allow inihbitory drive for expiration
DRG
Which neurones allow inihbitory drive for inspiration
Botzinger complex
VRG expiration component
What does the pontine respiratory group do
Influence the timing of breaths
Apart from sensory information from mechanoreceptors and chemoreceptors what other factors drive the DRG activity
Higher centres
What senses feed into the higher centre
Temperature
Pain
Emotion
Movement
What type of control is the behavioural system
Voluntary
Does the cerebral cortex which is driven by the behaviour system control the activity of the brainstem nuclei
No
Which situation can affect the brain activity
Exercise High altitude Respiratory stimulants (drugs) Sleep Depressed ventilation drugs
Which drugs stimulate respiration
Doxapram
Progesterone
Aminophylline
What does the respiratory stimulants do
Increase ventilation and reduce paco2
How does sleep affect breathing
Decreased response to hypoxia and hypercapnia
Decreased responce to mechanoreceptors
Which drugs depress ventilation
Anaesthetic Barbiturates Opioids Benzodiazepines Alcohol
