ONE of the things to which most people pay little attention is the roof. They only pay attention to it begins to rain heavily and it starts to leak.
If you have had the opportunity to fly in a plane over Africa, you will know you have entered the African continent by the type of roof structures you will see.
In many countries in Africa the building of houses was not considered a permanent activity but a temporal one.
Many people in Africa in years gone by moved around looking for better land and water so the shelters were never permanent.
In many places the roofs shine at you from the sky because they are often made of thatched grass or corrugated iron sheets.
Many structures in Europe have outlived their owners by many centuries because of the quality of their roof.
Similarly one of the things people pay the least attention to is sleep until they begin to fail to sleep at night.
It is one of those activities that are very important to health, but most often ignored, sacrificed and abused.
What is sleep and what is its function?
If you have every flown from west to east or vise versa, you will have experienced the unpleasant phenomenon known as jet lag.
This is when you fly from say Zambia to the United States of America. You sometimes find that you will start yawning in the middle of the day and fail to sleep at night.
The body has an internal clock or Circadian rhythm that tells you this is now night and this is now day.
Certain chemicals called hormones or night chemicals are produced by a gland in the brain called the Pineal gland.
This hormone called melatonin tells the body that it is night time, and it can slow down.
So sleep is the state of body shut down in which the brain cleans up, tidies up its SMS, e-mail and twitter messaging systems.
Or more medically it replaces and repairs its neurotransmitters in readiness for the next day.
The questions that are often asked are, what are dreams then? Are dreams about foretelling the future or are they about reliving the past?
These questions have not been fully answered by medical science even today.
However, one way of understanding sleep is to be aware that it occurs in cycles of two key stages.
These are what can be called light sleep (Non-REM sleep) and deep sleep (REM sleep). In light sleep it is like the body switches off all the muscles and in deep sleep the brain itself switches off and the clean-up begins.
It is the deep sleep phase or Rapid Eye Movement phase of sleep that people often dream.
The easiest way to understand it is like when an electrician comes to fix the wiring in your house.
While he is in the process of doing his work you may find certain lights go on abruptly or off, or when the plumber is fixing the plumbing works, you may find water on the floor, before he actually gets the whole system working again.
Similarly dreams can be understood as a process of repacking of the mailing system of the body to get it ready for the next day. In the process the spillage or clean-up mess created is what is experienced as a dream.
What are some common disorders of sleep and what are their consequences?
An elderly doctor friend of mine was involved in an accident just outside Monze.
He was unhurt but his car was slightly damaged. Apparently he found he had driven off the road.
When he come round he found no other car had been involved, he started the car up and drove himself to the hospital.
The most likely explanation was that he fell asleep while driving.
Some people fall asleep during day time activities, a condition called narcolepsy.
This is an irresistible urge to sleep during day time activity. This is separate from someone who sleeps while listening to a boring lecture or speech.
These people go into deep sleep immediately and may even begin to snore.
It is normal for someone to sleep while the lecturer is giving their lecturer.
However, if the lecturer falls asleep while giving the lecture himself, that would be narcolepsy.
This tends to run in families and will begin in the early teens.
Narcolepsy is often associated with visual hallucinations, sleep paralysis (a feeling of being bound up and not able to move) and sleep-walking.
Grinding of teeth during sleep as well as sleep-talking are other sleep disorders.
Insomnia or failure to sleep is a common sleep disorder affecting up to 10 to 15 per cent of people.
The opposite condition is called hypersomnia or excessive prolonged sleep during the day or at night.
Insomnia or failure to sleep can be due to other underlying illness, in which case it is called secondary insomnia or if no underlying illness can be identified, it is called primary insomnia.
Many people have difficulty sleeping because of emotional disturbances such as anxiety, fear or depression.
What can I do to get sufficient sleep?
The minimum amount of sleep recommended for an adult is between seven and nine hours of sleep.
Sleep allows for the development of the brain in children. It helps with learning, memory and speed of reflexes responses.
There are a couple of things that one can do to ensure that you get good adequate sleep, these are:
1.    Exercise
2.    Eat little
3.    Environment support
Ensure you get adequate exercise during the day. This will physically exhaust your body and lead to good sleep at night.
If you live a sedentary life and do very little activity, the brain finds no incentive to sleep at night, since it has done no work during the day.
Avoid taking stimulants before bed time. These include coffee, tea and smoking cigarettes.
These foods contain stimulants that charge the brain, create an environment of overdrive, which induces wakefulness rather than sleep.
If you eat a very heavy fatty meal before bed, your tummy will be distended and you will be uncomfortable.
This will make it difficult for the body to shut down for sleep. Have small light meals for supper.
Eat the heavy meals for breakfast and lunch, but eat minimally before sleeping. Make sure you create a good environment for sleep.
This includes a comfortable bed, position and pillow. You will always sleep better and easily in an environment in which you feel safe.
It is a good thing to turn off your mobile phone when toning done for bed and keeping it away from your sleeping bed.
The phone can disturb your ability to sleep because phones, wireless routers and computer console will transmit radio frequency, which are non-audible that may disturb the brain in its attempt to sleep, just like the flight navigation systems can be interfered with by these gadgets on a plane.
Take sleep as an important part of your health, plan for at least eight hours of sleep per day. This will improve your work.