The Basics of Sleep
Most of us dream while we sleep. During REM sleep, our bodies’ activity rises to daytime levels, and our sympathetic nervous system gets active, helping with our automatic responses. This is the stage of sleep in which we experience the most vivid dreams. During the deepest stage, we remain nearly motionless, but our mind and body are active and we dream. If you’re unable to fall asleep, you should consider getting some professional help.
Although sleep used to be thought of as a passive activity, scientists have discovered that it is an essential part of human life. During this time, the brain engages in activities critical for life, such as learning, memory storage, and stress relief. As a result, sleep scientists spend many of their waking hours researching the brain’s activities during sleep and their relationship to physical and mental health. Getting less than 7 hours of sleep a night may be detrimental to your heart health.
The definition of sleep depends on several criteria, including the time of day, the presence or absence of specific physiological signals. Objective measures, such as electrophysiological activity, may be used to identify sleep. These criteria are not totally independent, but their congruence and synchronization are essential. Regardless of how the condition is defined, sleep has many similarities to wakefulness and vice versa. You may not experience these differences, but you can easily tell when you’re experiencing sleep or wakefulness.
Your brain’s thalamus has a significant role in sleep. During REM sleep, it talks to a structure in the brain called the hypothalamus. This structure produces the chemical GABA, which calms the arousal centers. This process also paralyzes muscles during REM sleep, which is the dream state. You may be dreaming. But this isn’t the only reason to sleep. You need to relax, because your body will need rest to rejuvenate.
After you reach Stage 1 of NREM sleep, you’ll enter Stage 2. This stage is characterized by slower heart rates and lower breathing rates. Your muscles relax and your brain waves become slow and steady. This is the most common of the four stages of sleep. Most people spend most of their time in Stage 2 and then transition into Stage 3 during the first half of the night. If you don’t experience these stages, you’re more likely to have a restless sleep.
You may also be suffering from a sleeping disorder. While sleeping pills can provide some relief in the short term, behavioral strategies and cognitive behavioral therapy are the best ways to improve your sleep. Narcolepsy, a condition which causes sudden and unplanned daytime sleepiness, is also a sleep disorder that requires medical attention. Narcolepsy requires additional testing. However, it’s easy to treat and can help you achieve better quality of life.
In humans, the stages of sleep are characterized by a relaxed posture and reduced goal-directed behavior. Many animals and humans adopt the “horizontal repose” posture when they are asleep, which implies a passive role in relation to their environment. However, the phenomenon of sleepwalking raises questions about the capacity of the brain to control these processes. Whether this is true in marine mammals or in humans is unknown. It is, however, important to recognize the different stages of sleep and what happens during them.