REST AND SLEEP

REST- a state of calmness, relaxation without emotional stress, and freedom from anxiety
SLEEP- an altered state of consciousness in which the individual’s perception of and reaction to the environment are decreased.
This can be discussed simply by considering the three basic research approaches:

• ELECTROPHYSIOLOGIC
• HORMONAL and
• NEURAL

ELECTROPHYSIOLOGIC

• The Electrophysiological approach centers on the polygraph recordings of electrical changes in the brain waves (EEG), eye movements (EOG) and muscle activity (EMG).
• This approach characterizes sleep as Non-Rapid Eye Movement sleep (NREM) and the Rapid-Eye movement sleep (REM).

Neural

• The Neural approach views sleep as an active process involving the RETICULAR activating system (RAS) and the interaction of Neurotransmitters.
• The RAS is a network of neurons in the medulla, pons and midbrain with projections to the spinal cord, hypothalamus, cerebellum and cerebrum.
• SEROTONIN is said to be the MAJOR neurotransmitter associated with sleep, produced in the median raphe nuclei of the brainstem.
• Serotonin decreases the activity of the RAS inducing sleep. REM sleep appears to be due to the influence of norepinephrine.

Hormonal

• The Hormonal approach views sleep as a pattern affected by hormones. MELATONIN from the pineal gland in the brain is secreted in enormous quantities during sleep.
• Its activity is influenced by the relationship of darkness and light.
• ACTH is also high during the early period of sleep and CORTISOL rises toward the end of the nighttime sleep period.
• GROWTH HORMONE and PROLACTIN also increase during deep sleep. 

Functions of Sleep
1. Restores normal levels of activity and normal balance among parts of the nervous system
2. Necessary for protein synthesis
There are two types of sleep identified:
1. The NREM sleep (or the non-REM sleep) and
2. The REM sleep ( rapid eye movement sleep)

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Sleep Variation