Sleep Flashcards
What is the purpose of sleep?
Provides healing, restoration to maintain health and well being. Rejuvenate the mind so you can function.
Short term sleep loss does what?
- Alters mood
- Decreases ability to concentrate
- Harder to make descisions
- Less participation in daily activity
- More recovery time
What kind of processes is sleep?
Cyclical, physiological and behavioural process
What effects does the complex system of hormone release during sleep do?
Decrease HR
Decrease BP
Decrease RR
Decrease O2 consumption
Decrease Temperature
What are the 3 processes controlling sleep physiology?
- Ultradian process
- Homeostatic process (Process S)
- Circadian process (Process C)
What is the Ultradian process?
occurs within sleep state and determined based on 2 stages:
What are the 2 stages of the ultradian process?
- NREM
- REM
What is Homeostatic process (Process S)?
dependent on sleepâwake cycle
What is Circadian process (process C)?
Maintain a state of wakefulness
What are the physiological purposes of sleep?
-Memory
- Daytime alertness
- Mood, stress level
- Processing of stored information for the day
- Social Functioning
- Decreased muscle tone
- Decreased urination
- Cell and tissue repair
- Brain tissue restoration
- Immune function, renal function
- Metabolism of glucose
- Hormone secretion
What are circadian rhythms?
The biological functions of most living organisms are regulated by circadian rhythms.
-repeats every 24hours
-Biological clock
What are biological responses to circadian rhythm?
Body temperature peaks in afternoonâdrops as the day moves on.
The body temperature drops sharply after individual falls asleep.
What factors affect ones circadian rhythm?
light, temperature, social activities, and work routines
What is the purpose of a circadian rhythm?
Synchronizes sleepâwake cycles (e.g., bedtime)
What does a circadian rhythm do depending on each individual?
Affects individualâs optimal time of day
What regulates sleep?
A sequence of physiological states integrated by central nervous system activity (e.g., hypothalamus, anterior pituitary).
Where is the sleep centre?
Hypothalamus
What does the hypothalamus secrete?
Hypocretins (orexins) -promote wakefulness
What does the anterior pituitary secrete?
Hormones that promote sleep
-e.g; melatonin
What does the RAS do in relation to sleep?
maintains alertness and wakefulness
-affects wake transitions
What region causes sleep?
Bulbar synchronising region
What does Adenosine do?
builds up in the blood when awake -body breaks it down during sleep
-lack of sleep alters adenosine levels
What does Melatonin do?
natural hormone
-Causes person to feel drowsy
What are the stages of NREM?
(Pre sleep period 10-30mins)
Stage 1-Light sleep
Stage 2- Sound sleep
Stage 3- Deepest sleep
What is Stage 1: NREM light sleep?
Lightest level of sleep (2-5% of adults sleep time)
o This stage only lasts a few minutes
o Person is unresponsive but easily aroused by sensory stimuli, such as noise. o Physiological activity begins to decrease, accompanied by a gradual fall in
vital signs and metabolism.
o Muscle tone is present.
o When awakened from this stage, a person feels as though he or she had been
daydreaming.
What is Stage 2: NREM sound sleep?
Sound sleep (can be easily woken) â (45-55% of adult sleep time)
o This stage only lasts 10-25 minutes o Relaxation progresses.
o Body functions continue to slow.
o Muscle tone remains present.
o Eye movements are absent.
o Accounts for the greatest proportion (45% to
55%) of total sleep time in adults.
What is stage 3: NREM Deepest sleep?
Delta sleep or slow wave sleep (SWS) â10% of adult sleep time
o Deepest period of sleep.
o Individuals difficult to arouse.
o Muscles become completely relaxed. o Vital signs significantly lower but still
within normal limits
o Parasomnias may occur (e.g., sleepwalking, enuresis [bedwetting]) o More prominent during the first half of sleep
o Previous missed sleep will result in more time spent in this stage
What occurs after Stage 3 NREM during the sleep cycle?
REM
-rapid eye movement
What is REM?
Period during sleep where dreams occur
Paradoxicalâ
o Rapid eye movements are present.
o Respirations irregular and shallow, variations in HR & BP o Dreaming occurs more frequently and is more complex
than in NREM sleep.
o This stage usually begins about 90 minutes into sleep o Loss of skeletal muscle tone occurs, gastric secretions
increase.
o The person is difficult to arouse.
o The duration of REM sleep increases
with each cycle.
How many cycles does one have during a night?
four to five times
How long does the first cycle last?
90 mins
How long are the cycles after the first one?
100-120 mins