Sleep as an altered state of consciousness Flashcards
What is sleep?
naturally occurring state of altered consciousness
What are the 3 biological rhythms of sleep?
- circadian
- infradian
- untradian
What is the circadian rhythm?
the body functions and activities that occur in a cycle of 24 hours
How long does the circadian rhythm last for?
24 hours
What is the internal factors of the circadian rhythm?
(endogeneous)
= suprachiasmatic nucleus that is found in the hypothamulus
What does the suprachiasmatic nucleus do?
controls levels of arousal and metabolism and hormones
What kind of hormones does the suprachiasmatic nucleus regulate?
- melatonin
- cortisol
- adrenaline
What does cortisol do?
released by the suprachiasmatic nucleus
= regulates alertness
What does more cortisol mean?
high cortisol = high alertness
What does melatonin do?
released by the pineal gland
= more melatonin = more sleepy
= released when it is dark
What does adrenaline affect?
heart rate and blood pressure
What are some external factors that affect the circadian rhythm?
light and dark
What are zeitgebers?
external factors that affect the circadian rhythm
What does endogenous mean?
internal factors that affect the circadian rhythm
What detects that it is light?
light sensors in our eyes
What happens when our eyes sense that it is dark?
eye sensors detect that it is dark
= signals the suprachiasmatic nucleus that it is dark
= suprachiasmatic nucleus tells the pineal gland to release melatonin
= melatonin is released and makes us sleepy
Where is your internal body clock found?
in the hypothamulus
What is a main environment cue that affects sleep?
light
What is the ultradian rhythm?
our bodies activities in a cycle of less than 24 hours
What is one cycle of the ultradin rhythm?
less than 24 hours
What types of sleep does the ultradian rhythm have?
REM + NREM
How many cycles of REM/NREM sleep do adults normally experience per night?
4-5 cycles
What are some examples of a circadian rhythm?
= sleep-wake cycle
= body temperature
= alertness
What are some examples of an ultradian rhythm?
REM and NREM
sleep cycles
How long does one cycle of sleep last?
one cycle is both REM and NREM
= lasts 90 minutes
What is a sleep cycle?
one period of REM and NREM
What is NREM sleep?
makes up 80% of total sleep time
= stages of sleep not associated with rapid eye movement
What happens in stage 1 of NREM?
Around 5 minutes
= decrease into true sleep
= enter hynogogic state (hypnic jerks = muscle twitches)
What happens in stage 2 of NREM?
10-25 minutes but increases in length over time
= sleep spindles occur (rapid bursts of brainwaves)
= eyes stop rolling + muscles begin to relax
= believe we weren’t asleep
What happens in stage 3 of NREM?
start of deep sleep
= harder to wake up = more groggy if woken
= heart rate and temperature continue to drop
= few minutes
What happens in stage 4 of NREM?
deepest stage of sleep
= people are hardest to wake
= groggy when woken
= 20-40 minutes
What is REM?
period of sleep where your eyes move rapidly for short bursts of time
How often does REM occur in one night?
4-5 times
What happens in REM sleep?
rapid eye movements
= irregular breathing
= body temperature is hard to control
What does the body do during REM sleep?
nerve impulses are blocked from below the neck
= muscles don’t move
What is a paradoxial sleep and why is it known as REM sleep?
Paradoxial = means the body appears to be calm on the outside but the brain is highly active
Does dreaming occur in REM or NREM sleep?
REM
What kind of sleep occurs in REM sleep?
light sleep
What kind of periods occur during REM sleep?
lengthen and occur closer together as the night goes on
= 1-5 = 12-15 etc
What stage of sleep will a sleeper only go through once in a night?
Stage 1 of NREM
Stage 3 and 4 of NREM will tend to do what as the night progresses?
decrease
