11 - Control of Breathlessness (asleep) Flashcards
What is apnoea?
the (temporary cessation) of breathing
What is the apnoeic threshold?
the level of blood gas that you need to maintain breathing
What do we use to measure sleep?
EEG (electoencephalogram)
What does an EEG look like when awake and alert?
high frequency, low voltage activity
What happens to the pattern on EEG as you fall asleep?
higher voltage, lower frequency
What does an EEG look like for REM sleep?
looks like wakefulness- high frequency and low voltage
what happens to the muscles when you fall asleep?
postural muscle activity falls
ocular muscular activity falls
What is REM sleep?
where you have dreams - the EEG looks similar to that of wakefulness - the brain in very active
What happens to the muscles in REM sleep?
Which muscles are the exception?
You have functional paralysis (by brainstem). This is probably to stop us acting out our dreams.
The 2 muscles that are spared functional paralysis are the eye (causes rapid eye movement) and the diaphragm (allows for breathing).
what happens to the proportions of REM and non-REM sleep as you go through the night?
the amount of deep sleep decreases and the amount of REM sleep increases (hence, the first cycle is a very deep sleep)
Which centre controls breathing and what does it send signals to?
the respiratory centre, send signals to the respiratory muscles
What are the 3 inputs to the respiratory centre?
- brainstem - for reflexes
this involves chemosensitivity AND strech sensitivity from the lungs - motor cortex - voluntary/behavioural
- limbic system- emotional
During sleep, which input is no longer used?
corticol control (i.e. control of the motor cortex) - voluntary behaviour
Where are the neurones in the brainstem found?
on the rostral-lateral medullary surface
What is the Pre-Botzinger Complex?
What kind of neurones are present?
the name given to the cluster of respiratory nuclei in the brainstem
They have early and late firing neurones, which reciprocally inhibit each other
