The Mysterious Processes That Regulate Sleep

You can’t ignore how well a good night’s sleep makes you feel. It’s the difference between being sluggish and cranky and feeling calm and relaxed. Sleep is essential for healthy brain function, and it’s critical to physical health in everyone. But many people don’t understand how it works, or why they need to get enough.

Scientists are working hard to discover the mysterious processes that regulate our sleep, and how it relates to mental and physical health. This article gives a glimpse into what sleep researchers are discovering—and what they’re still trying to figure out.

Getting enough sleep is important for a number of reasons, including maintaining alertness and attention, helping the body repair itself and build up resistance to illness and injury, and strengthening the immune system against infection. It is also necessary for a variety of mental functions, including memory and learning. For example, the brain creates connections between experiences during the day, and this process is helped by deep sleep. It is also a time when emotions are processed and stored, and it’s believed that sleep helps prevent depression and anxiety disorders.

People who don’t get enough sleep have a much greater risk of developing chronic health problems, such as heart disease, high blood pressure, diabetes and obesity. They are more likely to have mood disorders and to be at higher risk of accidents, such as motor vehicle crashes and falls. They are also less able to concentrate, think clearly and react quickly.

The need for sleep is thought to have developed as a result of the increased vulnerability of humans to attack by predators at night. It’s also possible that sleep may have evolved as a means to allow animals to avoid unnecessary exertion when the weather was bad or when they were sick.

There are several theories about why we need sleep, but no one fully explains it yet. Some experts believe that it’s an evolutionary survival strategy, while others point to the importance of a certain chemical in our body that signals sleep. Others say that our bodies are programmed to spend a certain amount of time sleeping because we need to recharge and restore our energy levels.

For most of us, sleep is a quiet time during which we don’t move very much. In general, the skeletal muscles are relaxed and there is no overt goal-directed behavior, although there are exceptions (like sleepwalking) and marine mammals can be seen to perform some of the same movements while sleeping as they do during the day.

The typical sleep cycle consists of three non-REM or NREM phases, then four to five periods of REM, which is marked by rapid eye movement and a pattern of brain waves that are similar to those in the wakeful state. During REM, the eyes move rapidly behind closed lids and breath rate is increased. This is the stage during which most dreams occur, and it is generally agreed that dreaming is a vital part of the sleep experience.