Sleep Flashcards
what is sleep?
a readily reversible state of reduced responsiveness to, and interaction with, the environment
what are the two types of sleep?
Non-REM, REM
what is the definition of non-REM sleep?
Idling brain in a movable body
what are the features of non-REM sleep?
slow, large amplitude
what are the EEG features of non-REM sleep?
- Partial relaxation of muscles
- Temperature and energy consumption are lowered
- Increase in parasympathetic
- Some non-narrative images
what are the 4 types of non-REM sleep?
N1, N2, N3, N4
what is the features of N1 sleep?
between sleep and wakefulness, brain produces theta waves, hypnagogic hallucinations (hearing and seeing things that aren’t there, repetitive movements. Boat, Tetris effect, falling), only lasts a few mins
what is the features of N2 sleep?
harder to awaken, more theta waves, sleep spindles (bursts of rhythmic brain activity – inhibit cognitive processes), K complexes (suppress cortical processes and help with memory processing), lasts 5-15 mins
what is the features of N3 sleep?
slow wave sleep, delta waves
what is the features of N4 sleep?
large EEG rhythms very difficult to wake up, sleep walking and talking
what is the function of non-REM sleep?
protein synthesis, cell division and growth, body repair + restoration
what is the definition of REM sleep?
active, hallucinating brain in a paralysed body
what are the features of REM sleep?
• Fast, low voltage fluctuations EEG activity, fMRI shows increased brain activity
what are the features of REM sleep?
Brain activity similar to wakefulness
Atonic muscles (total paralysis) - except diaphragm and extraocular muscles
Dominant control via sympathetic system
Narrative dreaming
what does parasympathetic stimulation in Non-REM sleep cause?
reduced cerebral blood flow, reduced heart rate, blood pressure and tidal volumes