sleep and its functions

• sleep

  The body’s rest cycle

  a recurring state of relaxation that is characterized by an altered state of consciousness, inhibited sensory activity, muscular inhibition, and severely reduced interaction with outside entities
• anatomy of sleep Process of How We Transition from Wake to Sleep Cycle
• Hypothalamus promote wakefulness by sending arousal signals to the cerebral cortex, the brain’s largest region. These signals come in the form of chemicals called neurotransmitters. When neurons in the arousal areas are active, the cortex remains activated and we stay awake.
• Ventrolateral Preoptic nucleus of the hypothalamus is one area of the brain that is particularly involved in the switch between wakefulness and sleep.
• Ventrolateral Preoptic Nucleus connects directly to the many arousal-promoting centers, rather than stimulating activity in these areas, signals from VLPO neurons inhibit their activity. By shutting down the arousal centers, the VLPO promotes sleep.
• Gamma-Aminobutyric acid which acts to reduce the activity of arousal center.
• Sleep promoting cells within the hypothalamus and the brain stem produce a brain chemical called Gamma-Aminobutyric acid
• Suprachiasmatic Nucleus tiny region of the brain in the hypothalamus, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms.
• Pineal Gland located within the brains two hemispheres, receives signals from the SCN and increases production of the hormone melatonin, which helps put you to sleep once the lights go down.
• THE 4 STAGES OF SLEEP

  Stage 1

  Lightest stage of NREM sleep. Transition between waking and sleep when muscles relax and starts to drift off. People in this stage of sleep can be very easily woken up.

  Microsleep occurs at this stage. It is a very short sleep that lasts for less than 30 secs.

  Hypnic Jerks are experienced during this stage. It lasts for around 10 minutes or more.
• THE 4 STAGES OF SLEEP

  Stage 2

  • The body is truly asleep.
  • 40 – 50% of sleep are spent in this stage.
  • Heart rate begins to slow and the body temperature starts to drop.
  • The brain begins to produce sleep spindle intermixed with K complex. The latter two serves as protection for the brain from awakening as the body is preparing for deep sleep.
• Stage 3

  • Is also known as Deep NREM sleep.
  • NREM 3 takes time to adjust when awoken. most restful stage of sleep.
  • During the deep stages of NREM sleep, the body repairs and regrows tissues, builds bone and muscle, and strengthens the immune system. parasomnias occurs in this stage
• THE 4 STAGES OF SLEEP

  • Rapid Eye Movement Sleep
  • During REM sleep, our brain is almost as active as it is when we are awake.In this phase of sleep, breathing can become fast and irregular.
  • REM sleep is thought to help consolidate memories.
  • Drinking alcohol before bed reduces the amount of REM sleep we have.
  • People with REM sleep behavior disorder act out their dreams.
• REM SLEEP:

  Fast and irregular breathing.

  Increased heart rate (to near waking levels).

  Changes in body temperature.

  Increased blood pressure.

  Brain activity similar to that seen while awake.

  Increased oxygen consumption by the brain.

  Sexual arousal in both men and women.

  Twitching of the face and limbs.
• Sleep is essential to protect the mental and phyh of an individual, in addition to improving the quality of life. Hosical healtwever, the function of sleep has not always been clear and until recently the main function was believed to be the avoidance of sleep deprivation.
• During sleep, there are a number of important processes that occur to support the healthy function of the brain and overall physical health, which are particularly important for children and adolescents.
• Brain Function

  Sleep plays an important role in the function of the brain, by forming new pathways and processing information.

  When an individual has had insufficient sleep, physical changes occur in the brain, which alter the activity and function of the brain.

  Individuals that have not had adequate sleep may have difficulty making decisions, problem solving, controlling emotions and coping with change.

  Lack of sleep is also associated with depression, suicide and risk-taking behavior.
• Sleep plays an essential role in the consolidation of memory and the selection of important information and stimuli received throughout the day. Naturally, individuals don’t remember every detail but tend to prioritize certain information, due to an emotional or other connection.

  It is believed that sleeping and dreaming help in the process of sorting through experiences and memories to isolate and store the gist or specific detail of the memory.
• Sleep is also essential for maintenance of physical health of the body, particularly in the healing and repair of cells, such as those in the cardiovascular system.
• Advantages of Having Sufficient Sleep

  To reduce stress

  To improve your memory

  To be able to lower your blood pressure

  To help you to maintain your weight

  To put you into a better mood

  To help you to keep healthy

  To be able to reduce your chances of getting a diabetes

  To help you to keep your heart healthy

  To be a painkiller

  To be smarter
• Disadvantages of Sleep Deprivation

  Sleepiness Causes Accidents

  Sleep Loss Dumbs You Down

  Sleep disorders and chronic sleep loss can put you at risk for:

  Heart disease Heart attack Heart failure Irregular heartbeat High blood pressure Stroke Diabetes
• Lack of Sleep Kills Sex Drive Sleep deprivation causes Depression Sleepiness makes us forgetful. Losing sleep can make you gain weight. Sleep loss impairs judgement
• insomnia a sleep disorder that is characterized by difficulty falling and/or staying asleep.

  Symptoms:

  Difficulty falling asleep

  Waking up often during the night and having trouble going back to sleep

  Waking up too early in the morning

  Feeling tired upon waking
• Causes of Insomnia Anxiety, stress, and depression Medical problems or illness 3. Medications 4. Other sleep disorders
• Primary insomnia - means that a person is having sleep problems that are not directly associated with any other health condition or problem.
• Secondary insomnia - means that a person is having sleep problems because of something else, such as a health condition (like asthma, depression, arthritis, cancer, or heartburn); pain; medication they are taking; or a substance they are using (like alcohol).
• Acute insomnia - Short-term insomnia (1 night-few weeks)  
• Chronic insomnia - Long-term insomnia (3 nights a week-3 months)
• Sleep Apnea a potentially serious sleep disorder in which breathing repeatedly stops and starts.

  Symptoms:

  Loud snoring

  Episodes in which you stop breathing during sleep — which would be reported by another person

  Gasping for air during sleep

  Awakening with a dry mouth Morning headache

  Difficulty staying asleep (insomnia)

  Excessive daytime sleepiness (hypersomnia)

  Difficulty paying attention while awake

  Irritability
• Obstructive sleep apnea - the more common form that occurs when throat muscles relax
• Central sleep apnea - occurs when your brain doesn't send proper signals to the muscles that control breathing
• Complex sleep apnea syndrome - occurs when someone has both obstructive sleep apnea and central sleep apnea  
• Restless Legs Syndrome or Willis-Ekbom Disease

  a condition that causes an uncontrollable urge to move your legs, usually because of an uncomfortable sensation. Typically happens in the evening or nighttime hours when you're sitting or lying down.
• Causes of RLS 1. Crawling 2. Creeping 3. Pulling 4. Throbbing
• Hypersomnia a condition in which a person has trouble staying awake during the day
• Hypersomnia Symptoms: Excessive sleep

  Excessive daytime sleepiness

  Difficulty waking from sleep

  Sleep inertia/drunkenness

  Taking long, unrefreshing naps.

  Cognitive dysfunction.
• Causes of Hypersomnia

  1. The sleep disorders narcolepsy (daytime sleepiness) and sleep apnea (interruptions of breathing during sleep) 2. Not getting enough sleep at night (sleep deprivation) 3. Being overweight 4. Drug or alcohol abuse 5. A head injury or a neurological disease, such as multiple sclerosis or Parkinson's disease 6. Prescription drugs, such as tranquilizers or antihistamines 7. Genetics (having a relative with hypersomnia) 8. Depression
• Circadian Rhythm Disorders

  disruptions in a person's circadian rhythm -- a name given to the "internal body clock" that regulates the (approximately) 24-hour cycle of biological processes
• Circadian rhythm disorders Symptoms: Difficulty initiating sleep Difficulty maintaining sleep Nonrestorative sleep Daytime sleepiness Poor concentration Impaired performance, including a decrease in cognitive skills Poor psychomotor coordination Headaches Gastrointestinal distress
• Causes of Circadian Rhythm Disorders 1. Shift work 2. Pregnancy 3. Time zone changes 4. Medications 5. Changes in routine such as staying up late or sleeping in 6. Medical problems including Alzheimer's or Parkinson disease 7. Mental health problems 8. Menopause