Sleep spindles and K-compiexes are seen in which stage of sleep?
Ans. c. Stage 2 NREM (Ref: Ganong 24/e p273; Guyton ll/e p741-743)Sleep spindles and K-complexes are seen in stage 2 NREM of sleep.'There are two different kinds of sleep: rapid eye movement (REM) sleep and non-REM (SREM), or slow-wave sleep. NREM sleep is divided into four stages. A person falling asleep first enters stage 1, which is characterized by low-amplitude, high-frequency EEG activity. Stage 2 is marked by the appearance of sleep spindles. These are bursts of alpha-like, 10-14 Hz, 50 uV waves. In stage 3, the pattern is one of lower frequency and increased amplitude of the EEG waves. Maximum slowing with large waves is seen in stage 4. Thus, the characteristic of deep sleep is a pattern of rhythmic slow waves, indieating marked synchronization. - Ganong 24/e p273EOG, electro-oculogram registering eye movements; EMG. electromyogram registering skeletal muscle activity; CENTRAL, FRONTAL, OCCIP, three EEG leads. Note the low muscle tone with extensive eye movements in REM sleep.EEG Patterns In Sleep Beta (b) WaveAlpha (a) WaveTheta WaveDelta WaveSeen in* Parietal and frontalQ region* Patients awake, at rest with eyes openQ* Recorded from parieto occipital regionQ.* Seen in awake patient at rest with eyes closedQ* Seen in hippocampusQ in childrenQ and drowsiness* Seen in deep NREM sleepQ and infantQFrequency> 14 HzQ8-13 Hz4-7 Hz3-5 Hz (minimum)QAmplitudeLow amplitudeHigh amplitudeHigh amplitudeQLarge amplitude (Maximum)Q EEG Pattern In SleepNon Rapid Eye Movement (NREM) SleepRapid Eye Movement (REM) SleepAlso known as Slow wave sleep or Orthodox sleepQ(70-80% of total sleepQ)Also known as Paradoxical sleepQ(20-30% of total sleep)Stage 1:* First and lightest stage of sleep.* Predominantly theta wavesQStage 2: Characterized by-* Sleep spindlesQ* K-complex (easily evoked)QStage 3: (deep sleep transition)* Delta wave first appearQ* K-complex (with strong stimuli only)*Stage 4: (Cerebral sleep)* Predominant delta activityQ* Light phase of sleep, but arousal is difficultQ* Mixed frequency, low amplitudeQ waves on EEG. Predominantly b- like activity.* Also known as DesynchronizedQ or paradoxical sleep (because EEG is rapid)* Dreaming is seenQ* Active sleepSleep disorder during NREM IVSleep disorder of REM (3N)* Sleep walking (Somnambulism)Q* Sleep talking (Somniloquy)Q* Night terrorQ (Pavor nocturnes)* BruxismQ (tooth grinding)* Nocturnal enuresisQ (bed wetting)* Night maresQ* NarcolepsyQ: The hallmark of this disorder being decreased sleep latency.* Nocturnal penile tumescenceQ
REM
Stage 1 NREM
Stage 2 NREM
Stage 3 NREM
Sleep Physiology