4: KKDP 6 Sleep Wake Cycle Flashcards
Sleep:
An altered state of consciousness that features the suspension of awareness of the external environment and is accompanied by a number of physiological changes to the body
The need for sleep:
In innate in humans
Sleep is considered to be a:
Biological rhythm
The Sleep-Wake cycle:
A circadian rhythm that roughly follows a 24 hour cycle
The Sleep-Wake cycle is controlled by:
Our internal ‘body clock’
Melatonin:
A hormone associated with alertness
Melatonin is secreted:
In sunset/dusk, when there is less sunlight more melatonin is secreted, makes us drowsy
In sunrise/morning, when there is more sunlight, less melatonin is secreted, makes us alert
Ultradian Rhythm:
A biological rhythm that follows a cycle of less than 24 hours.
Key feature 1:
4-5 sleep cycles during a night
Key feature 2:
The average length of each sleep cycle is 90 minutes
Key feature 3:
We progress through NREM stages 2,3 and 4 and than go back to NREM 3 and 2 in reverse order.
Key feature 4:
Deep sleep usually occurs in the first 1/3rd of the night
NREM Feature 1:
Divided into 4 stages (1,2,3 and 4)
NREM Feature 2:
80% of our sleep time
NREM Feature 3:
Decreases as the night progresses
NREM Feature 4:
Stages 3 and 4 only occur in the first couple of cycles,
NREM Feature 5:
Replenishes the body
REM Feature 1:
Indicated by movements of the eyes under eyelids
REM Feature 2:
20% of our sleep time
REM Feature 3:
Increases as the night progresses
REM Feature 4:
80% of dreaming occurs
REM Feature 5:
Dreams tend to be clearer and more vivid
REM Feature 6:
Replenishes the mind
