Sleep

SLEEP? Speaking of Sleep, OMG! I love to sleep. No sleep = torture for me!

So, let's begin with "What is sleep?"

Sleep is a periodic state of natural unconsciousness during which the brain's activity is not apparent. A sleeping person does not respond to low intensity sounds, touches, and other sensory perceptions that he or she would normally respond to immediately while awake.

Why do we need sleep?

Sleep helps the body restore and rejuvenate in many different ways...

1. Memory, Learning and Social Processes – Sleeping enables the brain to encode new information and store it properly. REM sleep activates the parts of the brain that control learning. The parts of the brain that control emotions, decision-making and social interactions slow down dramatically during sleep, allowing optimal performance when awake.
2. Nervous System – neurons used during the day repair themselves during sleep.
3. Immune System – Sleep enables the immune system to function effectively. During deep sleep, the body's cells increase production while proteins break down at a slower rate. Without proper sleep, the immune system becomes weak and the body becomes more vulnerable to infection and disease.
4. Growth and Development – Growth hormones are released during sleep, so sleep is vital to proper physical and mental development.

What are the stages of sleep?

There are five stages of sleep: stages 1, 2, 3, 4 and REM (rapid eye movement).

• Stage 1 (Drowsiness) – We drift in and out of sleep for about 5 to 10 minutes and can be awakened easily. Our eyes move very slowly and muscle activity slows.
• Stage 2 (Light Sleep) – Our eye movements stop and our brain waves become slower, with occasional bursts of rapid waves called sleep spindles. Our heart rate slows and body temperature decreases.
• Stages 3 and 4 (Deep Sleep) – Slow brain waves begin to appear, interspersed with smaller, faster waves. By Stage 4 the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called deep sleep. There is no eye movement or muscle activity. People awakened during deep sleep do not adjust immediately and often feel groggy and disoriented for several minutes after they wake up. Some children experience bedwetting, night terrors, or sleepwalking during these stages.
• REM Sleep – During REM sleep, our breathing becomes more rapid, irregular, and shallow, our eyes jerk rapidly in various directions, and our limb muscles become temporarily paralyzed. Our heart rate increases, our blood pressure rises. People dream during this stage.

The average length of time for a complete sleep cycle is 90-110 minutes. About 50 percent of sleep time is spent in stage 2 and about 20 percent in REM sleep. The remaining 30 percent is split among the other stages. On average, a person will cycle through the stages 4 or 5 times in an eight hour period. After a person falls asleep, the first REM sleep period generally happens 70-90 minutes later.

The first cycles of the night will tend to have shorter REM periods and longer periods of deep sleep. This trend reverses as the night goes on. The later cycles have longer REM periods and shorter deep sleep periods. By morning, most sleepers spend almost all of their time in stages 1, 2 and REM sleep with very little or no deep sleep (stages 3 and 4).

How much sleep do we need?

Each person’s sleep requirement is different. Some people find that they only need 5-6 hours of sleep, while others need 10-11 hours for optimal performance. The average adult functions best with 7-8 hours of sleep a night; however, it is important to consider how much sleep you need on an individual basis.

• Infants and Children – Infants require about 16 hours a day. From 6 months to about 3 years, children’s sleep requirement decreases to about 14 hours.
  
• Teenagers – Teenagers need about 9 hours of sleep a night. Sleep is crucial for teenagers because it is while they are sleeping that their bodies release a hormone that is essential during their growth spurt.
• Adults – For most adults, 7 to 8 hours a night appears to be the best amount of sleep, although the amount ranges from 5 hours to 10 hours of sleep each day depending on the individual.
  
• Pregnant Women – Women in the first trimester of pregnancy, and sometimes throughout pregnancy, need significantly more sleep than usual.

How do we know if we are getting enough sleep? How will sleep deprivation affect me?

Some of the signs that indicate you may need more sleep include:

• difficulty waking up in the morning,
• inability to concentrate,
• falling asleep during work or class, and
• feelings of moodiness, irritability, depression or anxiety.

Getting less sleep than needed can cause a “sleep debt” . A person can make up for missed sleep during a night by sleeping more the next night, or compensate for missed sleep during the week by sleeping more on the weekend. Getting the missed sleep is important because the body needs it to recover and restore itself. Generally, people who aren’t getting enough sleep show mental and physical signs of sleep deprivation during their waking hours.

When you don’t get enough sleep, several things can occur:

• Impaired memory: Drowsiness during the day interferes with your brain’s ability to concentrate, learn and remember things.
• Physical impairment: Simple tasks may prove more difficult to perform and complex tasks may become seemingly impossible.
• Emotional response: You may become anxious, moody, and impatient, and notice increased difficulties during interaction and cooperation with others.

Severe sleep deprivation can lead to physical incapacity, hallucinations and mood swings. Proper rest supports the body’s ability to perform at its best whereas sleep deprivation impairs the body and mind, preventing optimal performance.

It is clear that sleep deprivation is dangerous –

• Sleep-deprived people who are tested by using a driving simulator or by performing a hand-eye coordination task perform as badly as or worse than those who are intoxicated.
• Sleep deprivation magnifies alcohol's effects on the body. A tired person who drinks will become much more impaired than someone who is well-rested.
• Driving while drowsy can - and often does - lead to disaster because drowsiness is the brain’s last step before falling asleep. Fatigue is responsible for thousands of car accidents each year and probably many other types of injuries and deaths as well. Caffeine and other stimulants cannot overcome the effects of severe sleep deprivation.

Get what I mean people? Sleeping is important!! Sleep more!! *oink oink*