Intro Flashcards
What are the components of the two process model of sleep?
- Circadian rhythm (body clock)
24 hour cycle, rhythmic, intrinsic, generated from SCN - Homeostatic drive (sleep pressure)
dependent on previous sleep quality and time awake
What is a Zeitberger?
An environmental agent/event that provides the stimulus for a biological clock
Which hormone causes sleepiness?
Melatonin
How long does a normal sleep cycle last?
Around 90 mins
What are the stages of sleep?
- Stage 1 sleep
- Stage 2 sleep
- Stage 3 sleep (slow-wave/deep) sleep
- REM sleep
How are sleep studies performed?
Polysomnography (+ECG)
What is a hypnogram?
A graphical representation of the stages of sleep as a function of time
What is stertor?
Noisy breathing during sleep, usually caused by obstruction at the level of the oral or nasal cavities or oropharynx or nasopharynx
- Typically low-pitched
What is stridor?
High pitched noise while sleeping, usually associated with obstruction at the level of the larynx
Where is melatonin produced?
The pineal gland
What is a normal Epworth sleepiness scale score?
If the patient has an Epworth sleepiness score of 10 then they should consider seeking medical advice
How many apnoea hypopnea events per hour is classed as normal?
< 5 events
What is the equation used for lung function predicted values and the age ranges?
GLI - available for over 3 year olds but only up to 80 year olds for the box
What do you measure with sleep pulse oximetry?
ODI (oxygen desaturation index), Total number of dips (<3), time below 90%, Nadir value
What is responsible for circadian rhythm and where is it located?
The suprachiasmatic nucleus (SCN) - located near cerebral cortex at the bottom of the brain
- in the anterior hypothalamus
Are circadian rhythm and homeostatic drive linear?
Circadian rhythm - is not (dips at 3pm)
Homeostatic drive is
Where is melatonin produced?
Pineal gland
How can you determine which stage of sleep patients are in?
Polysomnography - each stage has different waveforms
Which stage of sleep is deep sleep?
Stage 3 (delta sleep) - big delta waves seen
What waves are seen in REM sleep?
Low-voltage random, Saw-tooth waves
What polysomnography waves are seen when awake?
Low-voltage, random waves
What polysomnography waves are seen when drowsy?
Alpha waves - low voltage spikes
What polysomnography waves are seen when in stage 1 sleep?
Theta waves - short stubby waves
What polysomnography waves are seen when in stage 2 sleep?
Sleep spindles - small spikes
K complexes - massive rare spike