Module 34 - Sleep Flashcards
What is the behavioral definition of sleep?
Defined behaviourally: normal suspension of consciousness.
What is the electro-physiological definition of sleep?
- Defined electro-physiologically: Specific brain wave criteria (a series of precisely controlled physiological states)
- Governed by brainstem nuclei
How much does sleep consume our lives?
Sleep consumes ⅓ of our lives
Is sleep well understood?
Most of the details about sleep are poorly understood but its clinical importance is obvious
I.e. acute/chronic lack of sleep can interfere with daily activities
Why do we sleep? Animals are particularly vulnerable while sleeping… must have a considerable advantage.
- Replace glycogen levels
- Colder at night (efficient energy expenditure)
- Humans and other animals are dependants on vision/light
- Memory consolidation
True or false: the adverse effects of lack of sleep are well documented.
TRUE
What happens when you don’t sleep?
Sleep deprivation can lead to reduced cognitive function (problem solving and memory) and concentration.
What are some of the specific brain regions that are known to be particularly vulnerable to sleep deprivation?
…“specific brain regions involved with certain neurocognitive domains, including executive attention, working memory, and higher cognitive functions, are known to be particularly vulnerable to sleep deprivation.”
Explain the example of medical residents and how it is proof to what happens when you don’t sleep.
- Residents are more likely to have a motor vehicle crash or “near miss” after a night of on-call duty, or after a shift lasting 24 hours or longer.
- Sleep-deprived residents also have more attention lapses, experience more adverse events, and make more diagnostic errors while on duty overnight.
What is sleep debt?
Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental or physical fatigue. There are two kinds of sleep debt: the results of partial sleep deprivation and total sleep deprivation.
Does sleep debt need to be repaid very quickly?
YES, right away
Is fatigue a cause more vehicle accidents?
Yes
How is sleep across the lifespan?
- Most adults sleep for ~8 hours
- Infants and teenagers sleep more
- Older adults sleepless
Why do OT’s and PT’s care about sleep?
- OT = “Restful and adequate sleep provides the foundation for optimal occupational performance, participation, and engagement in daily life, a concept that is historically consistent with the development of occupational therapy.”
- PT = “Participation in an exercise training program has moderately positive effects on sleep quality in middle-aged and older adults. Physical exercise could be an alternative or complementary approach to existing therapies for sleep problems.”
What are circadian (once per day) rhythms?
- Most people sleep for ~ 8 hours a day, which is regulated by our circadian rhythm = to sleep once a day.
- Circadian rhythms are physical, mental, and behavioral changes that follow a daily cycle. They respond primarily to light and darkness in an organism’s environment. Sleeping at night and being awake during the day is an example of a light-related circadian rhythm.
True or false: Most people sleep for ~ 7 hours a day.
False: Most people sleep for ~ 8 hours a day.
You could potentially start sleeping at any point in the 24-hour cycle… So, how do we know when to sleep?
- Photoentrain: (synchronize) physiological processes with the day-night cycle
- “Biological clock” must be able to detect decreases in light levels as night approaches
- Both of these aspects = maintain daily rhythms in spite of the variable amount of daylight & darkness in different seasons + different locations on the planet.
What is the suprachiasmatic nucleus (SCN)
- “Master Clock”
- Specialized cells in ganglion layer of the retina contain melanopsin
- These cells convey information about environmental light levels information to the suprachiasmatic nucleus - located in the hypothalamus
- The SCN ultimately activates the pineal gland, modulating the production of melatonin.
- Melatonin in the bloodstream modulates SCN activity re: sleep/wake cycles
- Less light = more melatonin
What type of cells conveys information about environmental light levels information to the suprachiasmatic nucleus?
Specialized cells in ganglion layer of the retina contain melanopsin
Where is the suprachiasmatic nucleus located?
In the hypothalamus
The SCN ultimately activates the _______________, modulating the production of ______________.
The SCN ultimately activates the pineal gland, modulating the production of melatonin.
What modulates SCN activity re: sleep/wake cycles?
Melatonin in the bloodstream