Sleep structure and dreaming
Sleep is a periodic state of muscular relaxation reduced metabolic rate, suspended consciousness, in which a person is largely unresponsive to events in the environment. Sleep is essential for mental and physical restoration.
Five stages of sleep are distinguished by psychophysiological measurements:
* rapid eye movement (REM) sleep, the stage in which most dreaming occurs,
* and 4 separate stages – I, II, III, and IV non-rapid eye movement (NREM) sleep, the cycle is approximately 90 to 110 minutes.
Four stages of sleep take place during NREM (Non-REM sleep). Your brain is quiet, but your body moves around while you sleep. Hormones are released into the bloodstream and your body repairs itself after the wear and tear of the day.
* Stage I, when the person passes from relaxed wakefulness; “Pre-sleep” - your muscles relax, your heart beats slower and your body temperature falls.
* Stage II, an early stage of light sleep; “Light sleep” - you can wake up easily without feeling confused.
* stages III and IV, which are increasing degrees of deep sleep. Most stage IV sleep (also called delta sleep), occurs in the first several hours of sleep. “Slow wave” sleep - your blood pressure falls, you may talk or sleep walk and it's hard to wake up. If somebody does wake you, you feel confused.
A period of REM sleep normally follows a period of NREM sleep.
Rapid Eye Movement (REM) sleep (paradoxical sleep/desynchronized sleep) is a stage in the normal sleep cycle during which dreams occur and the body undergoes various physiological changes, including rapid eye movement, loss of reflexes, and increased pulse rate and brain activity.
Rapid Eye Movement (REM) sleep comes and goes throughout the night, and makes up about one fifth of your sleep. The brain is very active, eyes move quickly from side to side and you dream. Although your brain is active, your muscles are very relaxed (163).
You move between REM and non-REM sleep about 5 times during the night, dreaming more towards the morning.
On a normal night, most people wake up for one or two minutes every 2 hours or so. You aren't usually aware of these “mini wakes”, but may remember them if you feel anxious or there is something else going on - noises outside, a partner snoring etc. (163)
NREM sleep is non-rapid eye movement sleep, 75–80% of total sleep time in normal human adults. It is the deep, dreamless period of sleep during which the brain waves are slow and of high voltage, and autonomic activities, such as heart rate and blood pressure, are low and regular.
Non-REM sleep may be an anabolic state marked by physiological processes of growth and rejuvenation of the organism's immune, nervous, muscular, and skeletal systems.
Wakefulness may perhaps be viewed as a cyclical, temporary, hyperactive catabolic state during which the organism acquires nourishment and procreates.
The cycle of sleep and wakefulness is regulated by the brain stem, thalamus, external stimuli, and various hormones produced by the hypothalamus.
Sleep is a dynamic time of healing and growth for organisms. Sleep disorder is any condition that interferes with sleep.
If you have sleep related issues Counselling and Psychotherapy may be provided via Skype and FaceTime in the comfort of your home, office or any place of your choice.