Sleep Information

Sleep is a condition that is a necessary component of a person's overall functionality. Yet it remains a mysterious commodity, due in part to the fact that a person is in essence unaware of this function as it happens. While sleep may be basically defined as an interval of time where the body experiences rest, the actual components of sleep dictate something that is more complex.

What is Sleep?

Sleep is a naturally recurring state in a person's functional cycle that is marked by three distinctive traits. The first trait is a state of altered consciousness; that is, the entering into a state where a person is not aware of surroundings or external objects. The second trait is a generally inhibition of essential sensory activities, such as sight or hearing. The third trait is the inhibition of virtually all muscles that are not essential for the sustenance of life. This is a period where a person can experience a rejuvenation of various bodily processes that are connected to the immune, nervous, skeletal, and muscular systems. This rejuvenation enables the person to feel a sense of renewed energy and functionality upon re-entering a period of wakefulness.

Stages of Sleep

The overarching function of sleep is a gradual process that is marked by two states: REM (that is, rapid-eye movement) and Non-REM. The states themselves comprise four distinctive stages that occur during the sleeping process:

  1. NREM Stage 1 - This is the beginning stage of the sleeping process, where a person drifts from wakefullness into sleep. Typically, this is marked as an interval of roughly 5 to 10 minutes.
  2. NREM Stage 2 - This is the stage where the body prepares to enter the realm of deep sleep. During this stage, the heart rate will slow, the muscles will begin to relax, and the body temperature decreases.
  3. NREM Stage 3 - This is the stage known as slow-wave sleep, or SWS for short. It is marked by a decrease in environmental responsiveness to the point where the body becomes immune to stimuli that would otherwise provoke a reaction.
  4. REM - This is the state where muscles are paralyzed. It is sometimes known as paradoxical sleep because it has been shown that the sleeper produces EEG waves that are similar to those produced in a waking state, yet it is harder to arouse the sleeper into wakefulness at this state than at any other state in the cycle.

Sleep and Circadian Rhythm

The universal need for sleep during a specific cycle of time can be traced to a biological process known as circadian rhythm. This rhythm essentially represents the internal 'body clock' that is key to allow for proper timing in regards to the kinds of cellular and metabolic events that need to occur in order to keep a body in a proper level of homeostasis. This rhythm is defined by an endogenous period that lasts approximately 24 hours, and is typically set by external cues such as light and darkness.

The Importance of Dreams

One of the hallmarks of the sleeping state is the presence of dreams; successions of images and sensations that the mind involuntarily produces during certain stages of sleep. They have been noted to chiefly during the REM stage of sleep, although they can occur during other stages of sleep albeit with less vivid results. The range of dream length can last from a few seconds to up to 30 minutes. On average, a person will experience three dreams. While dreams have been the focus of study and interpretation for centuries, they are currently seen as a link to the unconscious mind.

How Much Sleep Do We Need?

The question as to how much sleep a person needs in order to achieve optimal performance is essentially dictated by two factors. The first factor has to do with the person's adherence to their circadian rhythm. The second factor is relative to a person's age. In the case of newborns, this amount ranges from 12 to 18 hours. For school age children aged 5 to 10 years, this range truncates to a range of 10 to 11 hours. For adults, this range further shortens to a range of 7 to 9 hours. If the parameters of these sleep intervals are not met on a consistent basis, then negative reactions associated with sleep debt may occur.

What is Sleep Debt?

Sleep debt, also known as sleep deficit, is essentially an aggregate condition brought about by not getting enough sleep. This aggregation is further defined as being the gap that develops between the sleep that a person should get and the sleep that a person is actually getting. Over time, this deficit can manifest itself into a host of mental and physical issues. These issues can range from minor items like irritability and severe yawning to much larger ramifications such as an impaired immune system and an increased risk of heart disease, type-2 diabetes, and obesity. Sleep debt can be .repaid,. but this sense of catching up on sleep is something that has to happen over the course of several nights as opposed to one extended evening of slumber.

The Importance of Napping

One of the more pleasurable experiences associated with sleeping is the act of taking a nap. This is defined as a short period of sleep that is typically experienced in the midst of daylight hours. It is usually initiated as a response to being drowsy during typical waking hours. Studies have shown that a nap ranging from 20 minutes to an hour will can aid in enhancing alertness, increasing mood, and elevating a person's overall productivity. Further studies have been able to link naps to promoting a lower risk of heart-related death.

Ultimately, all of these aspects represent the essential components that reiterate the importance of sleep. Collectively, these components strive to provide a consistent measure of homeostasis, both in terms of day-to-day functionality and long-term stability. Simply stated, without sleep, a person would not be able to properly function, if not survive outright.