Sleep Flashcards
How long do REM cycles go for?
90 minutes
What type of sleep is the deepest and most refreshing?
Stage 4
Which hormone controls circadian rhythms?
Melatonin
What happens to ventilation at the onset of sleep?
There is an initial drop then an compensatory increases in response to the greater CO2
During which sleep stage is PaCO2 the highest? Why?
REM because there is the greatest muscle relaxation
What are some effects of sleep deprivation?
Brain:
Irritability
Poor memory
Lethargy
Impaired moral judgement
ADHD symptoms
Severe yawning
Hallucinations
Heart:
Variable HR
Risk of heart disease
Risk of type 2 diabetes
Growth reduction
Increased weight
Decreased reaction time
Aches and tremors
Decreased temperature
What does EOG measure?
Eye movement
How does the structure of the elderly’s sleep compare to younger people?
More broken
Less total time
Less deep sleep
Why must muscles be paralysed during REM sleep?
Because there are movement commands from the corticol brain centre
Why is napping bad from insomniacs?
It reduces their drive to sleep later in the day so that they remain in debt
How many hours of sleep per night is associated with the lowest mortality?
7
What happens to upper airway resistance during sleep?
It increases due to muscle relaxation and the tongue dropping back
Depletion of what and accumulation of what lead to disinhibition of VLPO and the flipping of the switch towards sleep?
Depletion of ATP
Accumulation of adenosine
T/F as sleep deprivation increases and performance increases in a linear relationship, people are aware of their continuing lowering of performance.
False, their awareness of dropping performance tapers off
What type of sleep most commonly preceeds wakefulness?
REM
What levels of sleep deprivation are equvalent to a blood alcohol of 0.05%?
18-24 hours without sleep
5hours in 4-5 nights
Moderate-severe sleep apnoea
Return trans-altantic flight
Which muscle groups aren’t paralysed during REM sleep?
The respiratory and occular
Which area of the brain controls circadian rhythms?
Suprachiasmatic nucleus - it contains are biological clock
Where does the suprachiasmatic nucleus receive input from?
Light receptors of the eyes
The intergeniculate leaflet of the lateral geniculate thalamic nucleus
Why do people sleep?
Because you’ll get sleepy otherwise
Learning - consolidate learning
Brain development (REM)
Repair and maintenance
Energy preservation?
Keep out of trouble?
What does circadian rhythms encourage sleep?
Early afternoons and late evenings
How would you decribe the bodies’ movement during non-REM sleep?
Episodic and involuntary
What does EMG measure?
Muscle activity
During sleep which sensors are the most important for driving breathing?
The central and peripheral chemoreceptors
What does EEG measure?
Brain activity
Which age group has the highest amount of REM sleep? What percentage of their sleep does it make up?
Infants, 50% (cf to 25% in adults
During sleep, which sensors/inputs for control of breathing are lost?
Higher brain
Wakeful drive to sleep
Emotional stimuli
What is sleep characterised by?
Reduced responsiveness to external stimuli
Ability to return to wakefulness
Decreased aware of external environment
Stereotypical positions
Accumulation of debt
What happens to body temperature during the circadian cycle?
It decreases at night
How do sleeping paterns of the elderly differ from the typical?
They tend to sleep and wake earlier
