Why Do We Sleep?


Would it surprise you to know that our bodies and minds are just as active when we sleep as they are when we’re awake—maybe even more so? We’re not aware of it because we’re asleep, but critically important things happen in this “second state.”

The website howsleepworks.com states, “Sleep appears to be an essential physiological process for humans and for most other animals. When deprived of sleep, we function less effectively, feel tired and irritable, make more mistakes, are less creative and, if taken to extremes, ultimately die. In the same way, as a feeling of hunger reminds us of the basic human need to eat, a feeling of sleepiness reminds us of our essential need to sleep.”

Here’s a partial list of what we do when we’re asleep:

We shift into “rest and repair” mode. Our central nervous system has an autonomic mode that takes care of the internal processes that keep us alive. In our waking hours, we are largely in “fight or flight” mode, aware of potential threats to our wellbeing and worn down by daily stressors. During sleep, our bodies can focus on stabilization and maintenance: repairing and renewing tissues and nerve cells, neutralizing toxins, and restoring normal levels of chemicals throughout our bodies.

Wounds heal. Laboratory rats deprived of sleep show inferior healing capability, develop skin lesions, lose body mass, and struggle to maintain their body temperature, ultimately dying of sepsis or “exhaustion.” In humans, sleep is now associated with increased levels of growth hormones that contribute to tissue repair and regeneration (healing small muscle tears, for example).

The immune system gets a boost. It’s actually sage advice when folks tell us to get lots of rest when we’re sick or injured. Sleep-deprived rats had substantially fewer leukocytes—the while blood cells that help fight infection. Sleep deprived humans had less than half of the protective antibodies after receiving an inoculation as compared to people who had a healthy amount of sleep.

Brain power increases. Sleep is credited with increasing our brain plasticity—our ability to change and reorganize neural networks. REM sleep is so important, that when babies don’t get enough of it, it leads to developmental abnormalities later in life. During REM, we experience muscle “atonia,” a temporary paralysis of our muscles. It’s believed that this allows our brains to form new synaptic connections without risk of hurting ourselves by accidentally moving the wrong way. In other words, sleep allows conscious thought and motor activity to take a break so that the brain can work on other important functions.

Information is sorted and stored. Experts have long believed that new neural connections are made in the brain during sleep when external stimuli are minimal and no new information is being taken in. New research supports that during sleep, we convert short-term memories into long-term ones, and we re-consolidate long-term memories. Different kinds of sleep facilitate specific types of memories: visual memories vs. motor learning, emotionally neutral vs. emotionally charged memories, “declarative” memory (facts and events) vs. “procedural” memory (how to do things). This would explain why we have different sleep stages!

Brain power is boosted. Sleep seems to have a great impact on higher-level cognitive functions such as reasoning and decision-making. Getting enough sleep primes us for learning, “encoding” new memories more efficiently. When we learn something new, we perform the new task much better the next day after a good night’s sleep. By contrast, sleep deprivation leads to poor judgment, more accidents, and injuries.

Our brains clean house. There is evidence that during sleep, we “weed out” unnecessary and redundant memories and information, dumping information overload and keeping and sorting the important stuff.

Our mood improves. By contrast, sleep deprivation increases emotions like rage, fear, and depression. Sleep, especially dreams, facilitates creativity, flexible reasoning, and higher levels of understanding and knowledge.





Category : Blog &Health &Personal Growth Posted on January 23, 2018

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