What is the primary function of sleep?
Repair/restore mental and physical function
Sleep is necessary for memory consolidation and energy restoration.
What are the consequences of sleep deprivation?
- Skin lesions
- Compromised immunity
- Motor weakness
- Loss of executive function
- Disruption in homeostasis
- Death
What are the two main drivers of sleep?
- Sleep-Drive
- Circadian Rhythm
What is sleep-wake homeostasis?
The body’s internal drive to balance the need for sleep with the amount of time awake.
What chemical builds up in the brain while awake, signaling the need for sleep?
Adenosine
What happens to adenosine levels during sleep?
Adenosine is cleared away, resetting the sleep-drive cycle.
What role does caffeine play in sleep?
Blocks adenosine receptors
What regulates the circadian rhythm?
Suprachiasmatic nucleus (SCN) in the hypothalamus
What is a zeitgeber?
External cues that help synchronize our internal circadian rhythm.
What is the strongest zeitgeber?
Light
What is the primary characteristic of brain waves when awake?
Desynchronized - low voltage & high frequency
What occurs during Rapid Eye Movement (REM) sleep?
- Dreams occur
- Muscle atonia
- Irregular breathing & heart rate
What percentage of total sleep is REM sleep?
20-25%
How many cycles of sleep do most people go through each night?
4-6 cycles
What are the three stages of Non-Rapid Eye Movement (NREM) sleep?
- N1
- N2
- N3
What is the duration of NREM stage N1?
1-5 minutes
What is a key feature of NREM stage N2?
True sleep state with sleep spindles and K-complexes
What is the deepest phase of sleep?
NREM stage N3
What can occur during NREM stage N3?
- Sleepwalking
- Night terrors
- Enuresis
What characterizes acute insomnia?
Sleep disturbances occurring at least 3 nights per week, lasting less than 3 months
What is obstructive sleep apnea?
A disorder characterized by excessive daytime sleepiness and snoring
What is the primary treatment for obstructive sleep apnea?
Continuous positive airway pressure (CPAP)
What are benzodiazepines used for?
Short-term treatment of insomnia
What is a common side effect of nonbenzodiazepines?
Daytime drowsiness
