SciTech

How Things Work: Sleep

Credit: Molly Swartz/Art Staff Credit: Molly Swartz/Art Staff

Everyone knows that sleep is important, but many of us tend to let sleep take a backseat to all the other activities that fill our busy lives. Many combat a lack of sleep by taking naps in class or by indulging in a dose — or multiple doses — of caffeine. This may help us get through a day, but that lack of sleep can add up, and the consequences of consistently not receiving enough sleep can be detrimental.

Without sleep, many aspects of our body — such as muscle repair, memory consolidation, and the release of hormones — fall out of rhythm.

There are multiple stages of sleep, each of which individually contributes to rejuvenating the body. In the first stage, the body slowly becomes disengaged from its surroundings as the body temperature drops. As the body enters a deeper sleep, the brain remains active as the involuntary nervous system maintains breathing and a slower heart rate and relaxes the muscles. The most important aspect of this stage is the release of various hormones that travel through the body’s circulatory system. These hormones are essential for growth and development.

About 25 percent of human sleep is characterized as Rapid Eye Movement (REM), sleep that occurs at 90-minute intervals from when we fall asleep. During these intervals,our body releases high amounts of melatonin, activating pathways that play important roles in providing energy to the brain and body.

People typically experience most of their dreams during REM sleep. During dreams, areas of the brain associated with learning and memory are stimulated, and limb muscles become temporarily paralyzed so dreams are not physically acted out by the body. A single night’s sleep may produce many dreams, but people typically only remember the dream from the most recent REM phase. Currently, there is no consensus among the scientific community as to why people dream and what purpose dreams serve.

A survey by the National Sleep Foundation (NSF) found that 87 percent of people watch TV or use a computer within an hour before going to bed.
These bright lights can suppress the body’s output of melatonin, a chemical that controls sleep and wake biological clocks. Many students study late into the night on their laptops, which stimulates the mind instead of relaxing it, making it harder for the body to get the rest it needs.

Professionals at the NSF suggest that people should sleep in a place different from where they work so that the body recognizes a specific place, such as their beds, for sleep.

The amount of sleep necessary to maintain a healthy lifestyle drops slightly as a person ages, but doctors advise that teenagers and young adults should get 8–9 hours of sleep per night. HelpGuide.org states that trying to function the day after losing four hours of sleep can be equated to driving with a blood alcohol level of over 0.1 percent, which is over the legal limit.

In addition to the immediate effects of losing sleep, such as decreased productivity, the lack of sleep can lead to health problems in the future. Hormones released during sleep play important roles in preventing weight gain and lowering blood pressure. Without this regulation, one faces a higher risk of obesity, heart problems, and early-onset diabetes.