Get to know the essentials of sleep

Get to know the essentials of sleep

DR. S. YAMUNA

Sleep maintains the immune system and an adolescent requires a minimum of seven to eight hours of sleep a day.

SWEET SLEEP: Maintains physical, mental and academic health. PHOTO: MAHESH HARILAL

Seventeen year old Madhu had had a hectic study schedule from 5.00 am to 11.00 pm last year. On Sundays, too he was expected to maintain the same sleep rhythm for regularity. Though a school topper in Std. X, his performance dropped in Std. XI. He found it very difficult to keep awake during class. Moreover, he had to miss school many times in the previous year due to recurrent infections.

Normal brain activity

Thyroid dysfunction, anaemia, diabetes, depression and drug abuse were ruled out. Adequate sleep restored his function. His parents were advised to permit physical exercises and games in addition to intellectual stimulation.

Sleep is essential for normal brain activity and for restoring brain function. Stage One is between waking and sleep. During stage Two, there is a reduced sensitivity to outside stimulus. Three and Four are slow wave stages of deep sleep when brain recovers from the wear and tear of the day's activities.

Dreams, eye movements and drop in muscle tone characterise Rapid Eye Movement (REM) sleep, which starts within 90 min from the onset of sleep. The duration of REM sleep increases towards morning. REM sleep plays a crucial role in learning by consolidating the memories of the preceding day and by eliminating unnecessary recollections from the brain. More phases of REM sleep accompany intense learning on the polysomnograph. Those deprived of REM sleep perform poorly at a learnt task

Sleep maintains the immune system. The growth hormone is secreted in pulses during the slow wave sleep. Physical exercise enhances slow wave sleep stages three and four.

An adolescent needs a minimum of seven to eight hours of sleep per day. Pubertal development results in a biological and social shift in the sleep wake cycle with delayed bedtimes. A student who is woken up every day may be either in the slow wave or the REM sleep. Disturbances of either can inhibit normal learning processes.

A good night's sleep helps maintain physical, mental, social and academic health.

Dr. Yamuna is a Chennai based Consultant Paediatrician and Adolescent Physician.

e-mail: dryamunapaed@yahoo.com