Sleep Flashcards
What does the Reticular Activating system RAS do?
Sends impulses contributing to alertness to the limbic system and cerebral cortex. Once stimulated, it increases impulses leading to wakefulness.
what can happen if the hypothalamus is damaged?
Abnormal long sleep periods.
Which are the hormones involved in excitation?
Dopamine, Serotonin and Histamine.
What hormone is involved in inhibition?
GABA - causes drowsiness
Which hormone regulates the sleep-wake cycle and possibly the circadian rhythm?
Melatonin.
How many stages of non-rem/ NREM are there?
4
What characterizes Stage 1 of NREM, and what percentage of sleep occurs in this phase?
Light sleep state, can be easily woken - 5%
What characterizes Stage 2 of NREM, and what percentage of sleep occurs in this phase?
Light sleep, can be woken easily. Most sleep time happens in this phase - 50-55%
What characterizes Stage 3 of NREM, and what percentage of sleep occurs in this phase?
Deep sleep - you do not recall this sleep.
Parasympathetic nervous system dominates this phase and it also often referred to as Delta sleep or slow wave sleep. There is decrease in vital signs and metabolic rate however there is muscle movement.
10%
What characterizes Stage 4 of NREM, and what percentage of sleep occurs in this phase?
Deepest sleep - you do not recall this sleep.
Parasympathetic nervous system dominates this phase and it also often referred to as Delta sleep or slow wave sleep. There is decrease in vital signs and metabolic rate however there is muscle movement - Restorative sleep.
10%
What does REM stand for?
Rapid Eye Movement
What percentage of total sleep does REM sleep account for?
20-25%
What characterizes REM sleep?
The most vivid dreams occur in REM - You are able to remember your dreams. Brain waves resemble wakefulness and there is an increase in vital signs and metabolic rate. Skeletal muscles are depressed (REM atonia)
REM form a connection between short term memory and long term memory.
What does Polysomnia study?
Muscle activity, eye movement and brain activity during sleep.
What characterizes and older adults sleep pattern?
Frequently awaken at night
Don’t spend as much time in NREM stage 3&4 - mostly in 2nd stage, so they do not get as much restorative sleep.
They also spend less time in REM which has an impact on their short term memory which makes it harder for older adults to learn and remember new skills.
What fraction of our lives are spent sleeping?
1/3
If we do not get enough good sleep, what fraction of our life does lack of sleep affect?
2/3
How does sleep deprivation affect us neurologically?
It can lead to cognitive impairment and behavioral changes such as irritability and moodiness and lack of concentration and reaction time impairment.
How does sleep deprivation affect the endocrine system?
There is an increased risk of diabetes for chronic sleep deprivation due to it causing increased insulin resistance.
Decrease in growth hormone - decreases ability to heal. The body is not being repaired when it is experiencing sleep deprivation.