SLEEP DP 6-10 Flashcards
Sleep
- ASC marked by reduced metabolism and lowered consciousness
- consists of different stage each distinguished by physiological changes in HR, breathing rate, body temp, muscle tone
Hypnogram - sleep diagram
- graph showing sleep
- sleep in 1.5 hr cycles
- NREM periods decrease throughout the night
- REM periods increase throughout the night
REM
- Stage during the sleep cycle in which electrical brain activity is characterised by beta-wave patterns - high F, low A
- begins about 1.5 hours after falling asleep and returns 4-5 times a night
- EOG - rapid eye movement
- EMG - no muscle movement (atonia - muscle paralysis)
- dream
↑HR, ↑breathing rate, ↑body temp
20% of the night
NREM
- Stages of sleep which where individual is able to move (although usually doesn’t as brain isn’t sending signals to muscles to move) (little dreaming)
- Stages 1 & 2 - awaken easily and may not realise you were sleeping
- Stages 3 & 4 - difficult to wake up, if aroused, will likely be disorientated / confused
-Alpha, theta and delta waves
→ low F, high A - EOG - Slow rolling / no eye movement
- EMG - Little to no movement
- Hypnic jerks + some small movements
↓HR, ↓breathing rate, ↓body temp - Muscles are more relaxed, brainwaves are slow and rhythmical
80% of the night
Biological rhythms
A naturally occurring pattern of cyclic changes in bodily function that repeats itself over time
Circadian rhythms
Biological rhythm that involves changes in bodily functions that occur over a 24hr cycle
eg. daily sleep-wake cycle
Ultradian rhythms
Biological rhythm that involves changes in bodily functions that occur as part of a cycle shorter than 24 hours
eg. NREM/REM cycles of 90 mins within sleep period
Restorative theory
- Sleep replenishes our bodies and minds and allows us to recharge depleted energy resources that have been used up during waking time.
- REM - Replenishes psychological functioning, restores adequate neurotransmitter levels
- NREM - Replenishes physiological functioning, repairs damaged cells and tissues
Detoxifies muscles
Restorative theory - supportive evidence
Most people feel tired before they go to sleep and refreshed and more energetic upon waking (ppl also tend to sleep longer during an illness, suggesting that sleep may help the recovery process)
Restorative theory - limitations
An adequate amount of sleep does not guarantee good health
- Inactive people (such as disabled individuals who are confined to bed) should sleep less than the average active person, but actually experience the same proportions of NREM sleep.
Evolutionary theory
Survival/evolutionary trait
While sleeping, an organism isn’t physically interacting with the environment and is less likely to attract attention of potential predators
Evolutionary theory - supportive evidence
Furthers our understanding of the purpose/function of sleep
Provides a link between the circadian nature of sleep and when we sleep
Evolutionary theory - limitations
- Doesn’t account for the fact that sleep involves a loss of awareness that places individuals in a vulnerable position, as they are not ready to respond to danger if their muscles are in a relaxed state and senses are less attuned to surroundings
- Doesn’t explain our need for sleep, why we must and will eventually sleep, regardless of the environmental circumstance
Newborn
- 16 hrs
- REM 50% NREM 50%
- sleep onset occurs through REM sleep, not NREM stage 1
- each sleep ep only consists of 1-2 cycles
Teenagers
- 9-10 hrs
- REM 20%, NREM 80%