Brain is single most  vital organ of body. It weighs about one and half kilogram. It’s colour is mushroom grey white and consistency is gelatin like. Brain has millions and millions of functions. No super computer can duplicate the function of Brain. The brain comprises of brain cells called neurons. There are some thirty billion neurons. In between neurons there are non-functioning cells called glial cells. The gial cells amount to 300 billion about ten times of neurons cells. All these are kept in compact one and half kilogram size. Size of medium size cap.

By sheen structure all the so called wonders of the world will pale into insignificance when compound to brain.

Brain is not simply part of a body but brain is the person himself it’s entire personality in what is his brain capacity is.

If I ask a question how we see. Most of us answer we see through our eyes, but that is not true. Virtually there are sight centres in side brain where inter puts the vision and we see things. It because of some disease like tumour or stroke that position inside brain is affected we cannot see and inspite of eyes being healthy we will be blind.

Similarly hearings with ears, smelling with nose, tasting with tongue, feeling with skin, every thing happens inside brain. Brain governs, mood, like laughter, anger, pain pleasure. Sex. Fear anything and every thing. Brain tells the person when he is seek and when is hungry also.

Human brain function is often compared with function of a super computer. But super computer cannot cope with vast  informations, which a human brain does. Let us take an example. Super computer may give signal of an impending disaster like earthquake but cannot shift itself from the premises of the disaster. But brain of a person gives the signal of a disaster and asks the person to go to a safer place. A super computer cannot laugh, cannot  sing, cannot write poetry or create an art. So human brain is much beyond super computer. A super computer may be switched off. But brain is not.

Human brain also works during sleep. When there are too many informations brain selects the important ones and acts accordingly, suppose you want to listen a music and read at same time, you cannot do both. Reading a good novel, solving a puzzle or listening a music can never be simultaneously done. You have to give priority to a subject.

As you retrieve old data from a computer, so also you can retrieve data from your memory. Suppose five years back you had an accident at a particular place, say three hundred kilometers away, But when you pass through that particular place that event may flash over from your memory and you can vividly see things.

Function of brain being very vital, it is kept inside a well protected fortress called skull. The skull  is half a centimeter thick at the top and more thicker in the bases. Brain is bathed by an watery fluid called cerebra spinal fluid, C.S.F. in short. This fluid cushions the brain from shock. There is a blood brain barrier inside the brain which serves as a gate keeper. This gate keeper allows certain things inside brain like glucose and blocks certain things like bacteria or toxic substances. Unfortunately many poisons and alcohol pass the blood brain barrier.

A word about architecture of brain, you must have seen a grass field. If you take a chunk of grass with soil you will see lots of grass roots. So brain is like that in a bigger scale. Each of billion nerve cells (neurons) has root like out growths called dendrites and they are connected to each other, some are connected, 60,000 times. There are 30 billion nerve cells in the brain and many dendrites like spider nets. So please imagine the nature of nerves-working in the brain. Signals pass through the connections like dendrites with a speed of 340 kilometers per hour. After each signal passes, it takes 1/2000 of a second to recharge itself and again ready for duties by chemical means. Neurons never touch each other, signal pass through only sparks with each firing one nerve communicate with another through chemical means.

Peculiarity of brain cells: -

Brain cells do not reproduce like skin cells, liver cells or blood cells or any other cells of body. If one brain cell dies, then that dies for ever. By age of forty, a person looses about thousand brain cells daily. So as age advances, the brain cells loose weight. When enough cells are destroyed a person may loose hearing, taste or smell. That is why as age advances one person may loose attention span, and it becomes difficult in his part to remember names, dates, telephone numbers of near and dear ones.

Like Lungs or kidneys, brain is a paired organ with two hemispheres. The left hemisphere controls the right side of the body and right hemisphere controls the left side of body.

In right handed person, the left hemisphere is dominant and vice versa.

Then brain has earmark areas for different work. Area for hearings, seeing, tasting, smelling are different. So also past memories are stored in specific areas. So if one part is destroyed, other specialised works are not destroyed. Specialisation in brain is such perfect than other parts take lot of time to do the work of that part of brain. That is why it takes lot of time for the paralysed limbs to come back to life after a stroke.

Brain has four major diseases. They are  Infection, Stroke,  Tumour,  Injury.

Brain activity is increased by taking balanced diet, good exercises. Yoga and meditation.