It is our body's natural period of rest. We share the need with all mammals and birds and many fish, reptiles and amphibians. Restful sleep is essential for survival. While undergoing this unconsciousness our bodies and brains undergo two distinct phases. The famous REM or rapid eye movement is the relatively less common phase; the more common is known as non-REM. Alpha waves seen on an EEG of the brain indicate relaxation. With eyes closed and our mind free of thoughts, it is the first stage we undergo before going under. As drowsiness commences the alpha waves are replaced with delta waves, this stage indicates we have fallen asleep and entered the non-REM or slow-wave stage.
Slow wave is associated with muscle rehabilitation and growth through the release of anabolic hormones and cytokines. The cells of the body are repaired and immune defenses maintained. It helps us recover from the active rigors of the day. Pregnant women and fast-growing children and adolescents experience longer periods of slow-wave than those of us who no are not experiencing periods of growth. The non-REM phase can be divided into three phases. Stage 1 is the beginning. If you are woken at this stage it feels like you haven't been unaware at all. You will often experience hypnic jerks which are muscular twitches, typical before the next stage. Stage 2 is the next stage. It is still easy to be awoken from this stage though you are unconscious, this is the predecessor of stage 3.
Stage 3 or slow wave is what we call deep sleep. If you are woken during this stage then drowsiness and grogginess can be expected. This is also the stage where it is most difficult to wake someone. You will experience dreams at this stage though not nearly as memorable or vivid as those experienced during REM. Nightmares, night terrors and walking is most common during this phase. After 60-90 minutes of non-REM type, you will enter the first period of REM. This is characterized by rapid eye movement, muscle paralysis, and brain waves similar to the waking state. This first period will be short, around 5 minutes, but the cycle will continue through the night and periods of REM will get longer. The time spent should consist of around 20% of the total.
Dreaming and physiological arousal will be experienced while in the REM phase. Any dreams remembered the next morning will usually have occurred during this stage. It is theorized that the purpose of all this brain activity is to consolidate memories made during the day. Most medical professionals recommend about 7 to 9 hours for the normal amount of sleep a person should receive each night. Of course, the amount of time a person spends sleeping can vary by individual based on their age or overall lifestyle. If you are consistently tired after you get up from a full night's rest, and can barely stay awake during the day, you may have a serious condition known as Hypersomnia.
Slow wave is associated with muscle rehabilitation and growth through the release of anabolic hormones and cytokines. The cells of the body are repaired and immune defenses maintained. It helps us recover from the active rigors of the day. Pregnant women and fast-growing children and adolescents experience longer periods of slow-wave than those of us who no are not experiencing periods of growth. The non-REM phase can be divided into three phases. Stage 1 is the beginning. If you are woken at this stage it feels like you haven't been unaware at all. You will often experience hypnic jerks which are muscular twitches, typical before the next stage. Stage 2 is the next stage. It is still easy to be awoken from this stage though you are unconscious, this is the predecessor of stage 3.
Stage 3 or slow wave is what we call deep sleep. If you are woken during this stage then drowsiness and grogginess can be expected. This is also the stage where it is most difficult to wake someone. You will experience dreams at this stage though not nearly as memorable or vivid as those experienced during REM. Nightmares, night terrors and walking is most common during this phase. After 60-90 minutes of non-REM type, you will enter the first period of REM. This is characterized by rapid eye movement, muscle paralysis, and brain waves similar to the waking state. This first period will be short, around 5 minutes, but the cycle will continue through the night and periods of REM will get longer. The time spent should consist of around 20% of the total.
Dreaming and physiological arousal will be experienced while in the REM phase. Any dreams remembered the next morning will usually have occurred during this stage. It is theorized that the purpose of all this brain activity is to consolidate memories made during the day. Most medical professionals recommend about 7 to 9 hours for the normal amount of sleep a person should receive each night. Of course, the amount of time a person spends sleeping can vary by individual based on their age or overall lifestyle. If you are consistently tired after you get up from a full night's rest, and can barely stay awake during the day, you may have a serious condition known as Hypersomnia.
No comments:
Post a Comment