Why is sleep so important? During sleep, our metabolic activity and temperature lower to allow the body to conserve energy and apply this energy to growing new tissues, synthesizing new chemicals, and repairing body mechanisms. Blood supply to the muscles increases, energy is restored, tissue growth and repair occur, immune chemicals and cells are activated, and important hormones are released for growth and development. Electrical stimulation while we sleep helps cognitive (thinking, understanding, and learning) performance, decision-making, and memory when we are awake. Sleep is important for overall health and longevity. Studies have linked sleep disturbances to a number of diseases and illnesses.
Our brains have an internal clock that controls the stages of our sleep cycles. A nucleus of the hypothalamus in our brain crosses just above the part of the brain where the optic tract runs. Information on day length from the retina of the eye is passed to this nucleus and sent from there to the pineal gland. The pineal gland then secretes the hormone melatonin that induces sleep. Melatonin secretion peaks at night and ebbs during the daytime, therefore, the greatest desire for sleep is between midnight and dawn and, to a lesser degree, in midafternoon (about 2:00PM to 3:00 PM).
We spend about one-third of our lives asleep. When we sleep, stimulations like sounds, smells and physical sensations have very limited access to the brain. There are different stages of sleep where we are either easily awakened or not awakened by these stimulations. There are two kinds of sleep, Non-Rapid Eye Movement Sleep(NREM) and Rapid Eye Movement Sleep(REM). There are 5 stages of sleep within these two kinds of sleep.
Non-Rapid Eye Movement(NREM)
~ Also called “slow wave” or “quiet sleep
~ Consists of four stages: 1,2,3 and 4
~ Typically have a lot of body movement but an idling brain
~ 50% of infant sleep, 80% of adult sleep and 85% of elderly sleep
Rapid Eye Movement(REM)
~ Also called “paradoxical” sleep
~ Rapid eye movements and a paralyzed body
~ Vivid dreams that may help form long term memories.
~ 50% of infant sleep, 20% of adult sleep, and 15% of elderly sleep
Dreaming occurs during all stages of sleep, but mostly during stage 5 REM sleep. Theories of why we dream are numerous and wide-ranging. Dreaming is mostly visual, with limited sounds, touching, smells, and tastes (these remain vigilant during sleep to warn of threats). Just like conscious brain activity, dreams are composed of many kinds of thoughts and images. We also dream in NREM sleep. Nightmares and “night terrors” occur in NREM sleep.
In lucid dreaming, the dreamer can recognize that he or she is dreaming and can sometimes influence the course of the dream. Lucid dreaming occurs in REM dream sleep, but there is more focus in the images. Studies show that this awareness can be isolated and specifically targeted to control the content of the dream. Lucid dreams can sometimes be confused with hallucinations that occur while falling asleep or waking up during light sleep. There are some well-known examples of creative concepts and problem solving that resulted from dreams. Ludwig van Beethoven and Paul McCartney woke to find new tunes playing in their minds that inspired writing new music. Dmitry Mendeleyev woke up from a dream with the idea for the final form of the periodic table of elements. Mary Shelly dreamed the two main scenes from her classic book “Frankenstein”. Otto Loewi dreamed the neuroscience experiment that won the Noble Prize in medicine.
There is new technology such as positron emission tomography (PET) scans that allow us to see what parts of the brain are activated and involved in dreaming. The areas most active are the part of the cortex that involves visual imagery, the perception of movement, and emotion. Less active areas are the lobes associated with intentional action, logic and appropriateness of behavior. Therefore, there is less logical control over the content of dreams. They tend to be irrational, illogical and even bizarre in content. The areas of the cortex of the brain involved in smell, hearing, temperature changes, and pain are not turned off during sleep so that certain threatening stimuli can be monitored and result in wakening (e.g. the smell of smoke, the sound of intruders, heat of a fire, pain etc.)
Snoring and sleep apnea are causes of sleep and oxygen deprivation. Snoring has also been shown to double the risk of developing metabolic syndrome — a huge risk factor for diabetes, heart disease, and stroke. Medical and/or dental examinations should be done if you snore, which may also lead to a formal sleep study. There are simple remedies to help aid your snoring/sleep apnea episodes. Dr. Strembiski has extensive training in the treatment of snoring, sleep apnea, and airway obstruction. Please call our office if you would like a free consultation.
By: Shantelle Kitchen, R.D.A.