16 SLEEP Flashcards
What is the most mysterious thing we do?
Sleeping
Sleep is vital, but its exact purpose is not fully understood.
How much of our lives do we spend sleeping?
A third
This implies that sleep occupies a significant portion of human life.
What happens to the body when deprived of sleep for too long?
Death
The exact mechanism of death due to lack of sleep remains a mystery.
What biological processes are tied to sleep?
- Consolidating memories
- Restoring hormonal balance
- Emptying the brain of neurotoxins
- Resetting the immune system
What improvement was observed in people with early signs of hypertension who increased their sleep by one hour?
Significant improvement in blood pressure readings
This suggests a potential link between sleep duration and cardiovascular health.
What is the difference between hibernation and sleep?
Hibernation is not the same as sleep; it is more like being concussed or anesthetized
Hibernating animals still require conventional sleep.
What is the term for bears’ winter slumbers?
State of torpor
Bears do not hibernate as their body temperature remains near normal.
What is the primary phase of sleep where most dreaming occurs?
Rapid eye movement (REM) sleep
REM sleep accounts for about a quarter of total sleep time.
What is the phenomenon of waking up unable to move called?
Sleep paralysis
This condition can be unnerving but typically lasts only a few moments.
How many times do we typically change position during the night?
Thirty to forty times
Most people are unaware of these movements.
What are hypnagogic states?
Snatches of wakeful-hours sleep
This state occurs between waking and unconsciousness.
What are photosensitive retinal ganglion cells responsible for?
Detecting brightness
They help regulate circadian rhythms independent of vision.
What do the suprachiasmatic nuclei control?
Circadian rhythms
They act as the body’s alarm clocks.
What discovery did Russell Foster make in 1999?
A third type of photoreceptor in the eye
This discovery challenged long-held beliefs in the field of ophthalmology.
What percentage of sleep time do newborn babies spend in REM sleep?
At least 50 percent
For fetuses, it may be as much as 80 percent.
True or False: All mammals require the same amount of sleep.
False
Sleep requirements vary significantly among different species.
Fill in the blank: REM sleep accounts for up to _______ of every night’s sleep.
two hours
What is the average number of times people wake up briefly during the night without noticing?
Twenty-three times
This was observed in a sleep clinic study.
What is the possible evolutionary purpose of the hypnic jerk?
A fire drill to prevent falling
This theory suggests a protective mechanism during sleep.
What happens to some people’s limbs during REM sleep?
They remain paralyzed
This prevents movement during dreams.
What unusual phenomenon occurs during REM sleep related to male physiology?
Erections
This occurs not necessarily linked to erotic impulses.
What did a blind lady demonstrate about her brain’s ability to detect light?
She accurately identified when the lights were on or off despite having no vision.
This suggests that the brain can detect light at a subliminal level.
Where are body clocks located in humans?
In the brain and throughout the body, including pancreas, liver, heart, kidneys, fatty tissue, and muscle.
These clocks dictate hormone release and organ activity.
What are the consequences of disturbances to daily rhythms in the body?
They can contribute to diabetes, heart disease, depression, and serious weight gain.
Disruptions can lead to various health issues.
What hormone does the pineal gland produce?
Melatonin.
Melatonin helps the brain track day length.
How does melatonin production differ between young and older individuals?
Production falls significantly with age; a seventy-year-old produces only a quarter as much melatonin as a twenty-year-old.
The effects of decreased melatonin levels with age are still being studied.
What did Michel Siffre’s experiment in 1962 demonstrate about human perception of time?
He miscalculated the passage of time, believing 37 days had passed when it was actually 58.
This highlights the confusion of circadian rhythms without external cues.
What is one finding related to seasonal rhythms and social issues?
There are seasonal peaks in self-harm, suicide, and child abuse, shifted six months between the Northern and Southern Hemispheres.
This indicates a link between seasonal changes and human behavior.
What is the impact of circadian rhythms on medication effectiveness?
Around half of bestselling drugs are time-sensitive; taking them at the wrong time can reduce their effectiveness.
Timing can be crucial for drug efficacy.
What is sleep homeostasis?
A natural pressure to sleep that increases the longer one stays awake, influenced by adenosine accumulation.
Adenosine is a by-product of ATP output.
What is the typical range of sleep required for adults?
Seven to nine hours per night.
Sleep needs vary based on age, health, and recent activities.
What is the issue with early high school start times in the U.S.?
Many high schools start before 8:30 a.m., leading to poorer attendance and mental health outcomes.
Later start times can improve various aspects of student life.
What percentage of adults suffer from insomnia?
Between 10 and 20 percent.
Insomnia is linked to several serious health conditions.
What condition is characterized by the inability to breathe during sleep?
Sleep apnea.
It is more common than many people realize.
What is fatal familial insomnia?
A rare inherited disorder that leads to the inability to sleep and ultimately results in death.
It affects only about three dozen families worldwide.
What is narcolepsy, and what causes it?
A condition causing extreme drowsiness and difficulty staying awake, caused by a lack of hypocretin in the brain.
It affects about four million people globally.
What are parasomnias?
Sleep disorders including sleepwalking, confusional arousal, nightmares, and night terrors.
These are more common in children and often resolve around puberty.
What is known about the phenomenon of yawning?
The purpose of yawning is unknown, but it is highly contagious and occurs in various states of consciousness.
Yawning does not correlate reliably with energy levels.
What was Randy Gardner’s record for staying awake?
264.4 hours (11 days and 24 minutes).
He experienced irritability and confusion but returned to normal sleep patterns afterward.
What do teeth acquire over time that is similar to tree rings?
Daily microscopic accretions
These accretions help scientists determine how long it took children to grow up in the past.
At what age do teeth stop growing?
About the age of twenty
What is melatonin commonly used for in the United States?
Jet lag or insomnia
What is unique about the availability of melatonin in the United States?
It can be purchased without a prescription
What classification is melatonin considered under U.S. law?
Dietary supplement
Who discovered prions?
Dr. Stanley Prusiner
What severe condition did Dr. Prusiner investigate in a patient?
Sudden onset dementia
What was the initial reaction to Prusiner’s theory about prions?
It was widely derided
In what year did Dr. Prusiner win the Nobel Prize?
1997
What term describes the brain’s appearance after neuron death due to prion disease?
Spongiform
How long did Clare Southern stay awake during the Channel 4 television series Shattered?
178 hours
What was the record duration of staying awake that Clare Southern’s time fell short of?
More than three days less than Randy Gardner
True or False: Prions are infectious proteins that can cause severe neurological damage.
True
Fill in the blank: The death of neurons leaves the brain with cavities, resembling a _______.
Sponge
