16. Sleep Flashcards
(17 cards)
What is sleep?
An altered state of consciousness with reduced awareness of the environment, increased arousal threshold, typical resting posture, and stereotypical brain activity patterns.
Sleep is essential for various physiological functions and cognitive processes.
What are the two main drivers of sleep regulation?
- Homeostatic drive (Process S)
- Circadian rhythm (Process C)
Process S refers to sleep pressure building with wakefulness, while Process C involves the internal clock regulating sleep/wake cycles.
How can sleep be monitored?
Via electroencephalogram (EEG), which shows characteristic patterns.
EEG is a tool that records electrical activity in the brain.
What are the brain activity patterns in the awake state?
High frequency (15-60 Hz), low amplitude waves (beta activity).
Beta activity indicates alertness and active engagement.
What characterizes Non-REM sleep?
- Stage 1: Theta waves
- Stages 2-4: Delta waves (highest amplitude, lowest frequency)
Non-REM sleep is crucial for restorative processes in the body.
What happens to sleep cycles throughout the night?
- Early cycles contain more deep non-REM sleep
- Later cycles contain more REM sleep
Sleep architecture changes with age, leading to less deep sleep and more fragmentation.
What physiological changes occur during Non-REM sleep?
- Shift to parasympathetic activity
- Reduced heart rate and respiration
- Maintained thermoregulation
- Reduced muscle tone
These changes support restorative functions during sleep.
What characterizes REM sleep?
- Rapid eye movements
- Brain activity resembling wakefulness
- Increased heart rate and respiration
- Extreme muscle atonia (paralysis)
- Suspended thermoregulation
- Penile erection/vaginal lubrication
REM sleep is important for emotional regulation and memory processing.
What neurotransmitters promote wakefulness?
- Orexin (lateral hypothalamus)
- Histamine (tuberomammillary nucleus)
- Norepinephrine (locus coeruleus)
- Serotonin (raphe nuclei)
- Acetylcholine (brainstem cholinergic nuclei)
These neurotransmitters play crucial roles in maintaining alertness and wakefulness.
Which nuclei promote sleep?
Ventrolateral preoptic nucleus (VLPO) and medial preoptic area, which use GABA to inhibit wake-promoting nuclei.
GABA is a primary inhibitory neurotransmitter in the brain.
What is insomnia?
Difficulty falling/staying asleep, affecting ~10% of the population.
Insomnia is often related to anxiety and can create a vicious cycle of sleep disruption.
What is narcolepsy?
Excessive daytime sleepiness with sudden sleep attacks, often triggered by emotional experiences.
Narcolepsy involves cataplexy and is associated with loss of orexin-producing neurons.
What are sleep-related breathing disorders?
- Primary snoring
- Obstructive sleep apnea (blocked airway during sleep)
These disorders increase the risk of cardiovascular disease, diabetes, and depression.
What are circadian rhythm sleep disorders?
- Non-24-hour sleep-wake syndrome
- Delayed sleep phase syndrome
- Advanced sleep phase syndrome
These disorders can lead to irregular sleep patterns, particularly in adolescents.
What are the cognitive impacts of sleep disruption?
- Reduced attention and computational speed
- Decreased verbal fluency and creativity
- Impaired problem-solving abilities
- Learning deficits and lower IQ scores
Sleep is crucial for cognitive functions and overall mental health.
What did sleep deprivation experiments with rats demonstrate?
Severe health consequences, including death.
These experiments highlight the critical importance of sleep for survival and health.
Fill in the blank: Sleep enhances learning and ______.
[memory consolidation]
Memory consolidation is the process by which short-term memories are transformed into long-term storage.
