Sleep

 

Sleep

We sleep in cycles.

Each cycle is 90 to 120 minutes.

Three NREM (N1, N2 and N3) phases and one REM phase make a full sleep cycle.

N1  Stage 1, also called N1, is essentially when a person first falls asleep. This stage normally lasts just one to seven minutes. During N1 sleep, the body has not fully relaxed, though the body and brain activities start to slow with periods of brief movements.

N2 is Light Sleep

N3 is Deep Sleep

Memories are probably stored during deep sleep in a raw and random fashion.

NREM        =      Non Rapid Eye Movement

REM           =      Rapid Eye Movement

SCN          =      Suprachiasmatic nucleus

Suprachiasmatic nucleus regulates Diurnal Rhythm

In REM sleep memory is reorganised and redundant information is filtered off.

REM sleep is generally 25% of the total sleep and we tend to dream in REM sleep.

Memory is stored during REM.

REM starts as short bursts and as one sleeps longer REM tends to last longer.

We have 6 cycle per night.

We generally needs 8 hours of sleep out of which 4 hours of Deep Sleep is vital.

One need not worry about these stages  since these patterns are determined by autonomous melatonin secretion.

Approximately 75% of sleep is spent in the NREM stages, with the majority spent in the N2 stage. A typical night's sleep consists of 4 to 6 sleep cycles, with the progression of sleep stages in the following order: N1, N2, N3, N2, REM.

A complete sleep cycle takes roughly 90 to 110 minutes.

Alcohol can have a complex and often negative impact on sleep. While it may initially help some individuals fall asleep faster, it disrupts sleep later in the night, leading to poorer sleep quality and increased wakefulness. These disruptions can affect different sleep stages, particularly REM sleep, and may lead to daytime fatigue and impaired cognitive function.

Alcohol can initially make one feels drowsy and fall asleep faster.  Alcohol alters the normal stages of sleep, especially REM sleep, which is important for memory and emotional.  As the body metabolizes alcohol, it leads to more frequent awakenings during the second half of the sleep cycle. These disruptions can result in lighter sleep and feeling tired the next day. Alcohol can worsen snoring and sleep apnoea. Alcohol is a potential diuretic and waking up in mid cycle may disrupt the restoration intended. When alcohol is metabolized, there can be a rebound effect, leading to increased REM sleep later in the night.

To minimize sleep disruptions, avoid alcohol at least a few hours before bed. Consider reducing the amount of alcohol consumed, especially close to bedtime. The closer to bedtime alcohol is consumed, the greater the potential for sleep disruption. Drink plenty of water to counteract the dehydration that follow heavy drinking. Alcohol directly inhibits the release of melatonin, the hormone that promotes sleep. Alcohol can disrupts the natural circadian rhythm by interfering with the natural light and darkness, cycle which trigger melatonin production. Alcohol consumption can lead to less restful sleep and feeling less refreshed upon waking.