Which of the following is not true about sleep -
Ans. is 'a' i.e. REM sleep comes earlier than NREM sleep Stages of SleepA) Non-REM (NREM) or slow-wave sleep :- It is called Non-REM sleep because no rapid eye movement (REM) is there on eletro-oculogram, rather there is slow or quiscent eye movement. It is also referred as S-sleep (synchronized sleep) or quiet sleep or orthodox sleep because there diminished physiological functions and a low level of overall activity. It is further divided into:-1) Stage 1:- It is a transition from wakefulness to sleep and is characterized by disappearance of alpha activity and appearance of theta activity. There is slow eye movements.2) Stage 2:- It is characterized by typical EEG activity i.e., Sleep spindles and 'K-complex'. No eye movement occurs.3) Stage 3 & 4:- Stage 3 & 4 are stages of deep sleep. These are also called slow wave sleep as these stages are characterized by slow delta waves. Delta wave appearance starts in stage 3 and dominated in stage 4.B) REM sleep:- The REM sleep is so named as there is rapid roving movements of eye, i.e., rapid eye movement (REM) on electro-oculogram. It is also called paradoxical sleep because there is a paradoxical elevation of brain activity & metabolism and physiological activity. The high-amplitude slow waves seen in stage 3,4 of REM sleep is replaced by rapid low voltage activity (beta wave). Features of REM sleep are:-i) EEG - Beta wave, Reappearance of alpha wave, Saw-tooth wave (low voltage fast activity), Ponto-genital- occipital spikes.ii) Dreamingiii) Other features: - Generalized muscular atony, Penile erection, autonomic hyperactivity (Increased pulse rate & BP) and intermittent movement of small muscle groups.o The NREM (with its four stages) and REM sleep repeat several times a night in cyclic manner, 4-6 times depending on the length of sleep. A typical cycle starts with stage 1 of the NREM sleep which is followed by second, third and fourth stages. After this the sleep returns to stage 3 and 2. The first REM sleep occurs now, 70-90 minutes after the commencement of sleep (Note : - Stage 1 NREM sleep occurs only once at the start of the sleep as this is only a transition phase between wakefulness and sleep. Once the sleep starts the cycle rotates between stage 2, 3, 4 NREM and REM sleep). REM sleep occupies 20-30% of total sleep and NREM sleep occupies 60-70% (Stage- 1 - 5-10%; Stage 2 - 40-50%; Stage 3 & 4 - 15-20%).# Slow wave sleep (stage 3 & 4 of NREM sleep) disorders:- Sleep walking (somnambulism), night terror (sleep terror or pavomoctumus), Nocturnal enuresis, Bruxism (teeth grinding), and sleep talking (somniloquy).# REM sleep events/disorder:- Nightmares, nocturnal penile tumescence, Narcolepsy.
REM sleep comes earlier than NREM sleep
REM sleep is also called paradoxical sleep
Sleep walking comes in NREM sleep
Dreams come in REM sleep
Normal Sleep