Sleep Flashcards
Who is Michel Siffre?
He spent 2 months in a cave with no knowledge of time, resulting in free-running activity uncorrelated to time.
What are the main components of the brain contributing to the sleep process?
The suprachiasmatic nucleus, the hypothalamus, pineal gland and the glymphatic system.
What is the wake maintenance zone?
It is a period of time after staying awake where a person temporarily ceases to feel drowsy, unable to fall asleep even if exhausted.
What is the suprachiasmatic nucleus?
Located in the hypothalamus, the SCN controls our circadian rhythms, our biological clocks. It processes signals from melanopsin receptors in our eyes, inhibiting the production of melatonin within the pineal gland.
What is the pineal gland?
It produces melatonin, a hormone that increases our drowsiness.
What is the hypothalamus?
It regulates our body temperature and controls body fluid intake. It also contains the SCN.
What is the glymphatic system?
It is activated when slow waves of neural activity during sleep causes change in vasodilation (widening of blood vessels) in the brain. These changes pump cerebrospinal fluid that cleanses the brain of metabolic waste.
What happens to sleep patterns if you remove the SCN?
There is a similar amount of sleep obtained, but sleep is more disrupted; flitting between activity and sleeping.
What is the primary Zeitgeber?
Light provides us our sense of time by resetting our circadian rhythms through the melanopsin receptors in our eyes and activating the SCN.
What is the difference between phase delay and phase advance?
Phase advance is the achievement of resetting our circadian rhythms by waking up earlier, whilst phase delay involves waking up later.
What are the three theories of sleep and why we require it?
Inactivity: we are more vulnerable at night, hence it makes sense to sleep during that time to remain quiet and prevent detection. however, it would make more sense have consciousness at night.
Energy Conservation: we are inefficient at foraging for food at night, hence we sleep during this time to save energy.
Recovery: Sleep helps us to recuperate, grow muscles, repair tissue, synthesise protein and release growth hormones. It also prevents certain diseases like Alzheimer’s, cancer, diabetes, etc.
Who is Peter Tripp (1959)?
He experienced psychosis as a result of not sleeping for 8 days.
Who is Randy Gardener (1964)?
He had moodiness, problems with concentration, short term memory, paranoia and hallucinations after not sleeping for 11 days.
What happens to rats deprived of sleep for 2 weeks?
They eventually died at 4 weeks, but not before losing weight and the ability to thermoregulate, and contracting infections.
How do we measure physiological reactions during sleep?
Electrooculogram (EOG) - eye movements
Electroencephalogram (EEG) - gross brain electrical activity
Electromyogram (EMG) - muscle activity
