the amazing brain

Have you ever imagined what you would be, if you do not have a brain or nervous system ?

 A mass of cells unaware of what is going around, unable to think, hear, see, remember, or reason out. Your muscles will misbehave just like players without a coach. And    your breathing, heartbeat etc will not be that fine-tuned as they are now. 

 

  Of all the animal brains human brain in proportion to the body size is the largest. The brain is a soft and delicate organ well protected inside a box made of bones called cranium. Inside cranium there are three protective membranes or Meninges. Inflammation of the Meninges is Meningitis and it is a deadly state of affairs.  The brain weighs 20% of the total body weight. The brain uses 20% of the Oxygen taken in by the body.  Are intelligence and brain size related? There is no scientific proof to substantiate this. The weight of human brain at adulthood is almost three times the weight of brain at birth. The average weight of brain of an adult male is 1.4 kg(3pounds) and that of an adult female is1.3 kg (2.9 pounds). Even though the brain size in males is slightly more when compared to that of the females, nobody has proved that all males are intelligent than females. Also in males  no proportion between brain size and intelligence or intellect is proved beyond doubt. The brain of Russian author Ivan Turganev (1813-1883) weighed 2.01 kg where as the brain of a contemporary French author Anatole France (1844-1924) weighed only half –1.01 kg! The left brain controls all activities of the right half of the body, neck downwards and vice versa. In right handed people the left brain controls reading, writing, talking etc and the right hemisphere of brain overlooks imagination, artistic talents etc. In left-handed people it is the other way round.  The nerve cell is known as neuron and the number of neurons in the brain is about 10 million. Brain alone is not the center of neurological activities. The spinal cord also is a part of the nervous system. Each neuron has an axon or a projection, which links the neuron to the nervous system. Some axons are so lengthy (more than a metre) making them the longest cells in the human body. The dendrons connect neurons together. Information from and to the brain is by way of electrochemical impulses from neuron to neuron. The electrochemical impulses are created by the change in distribution of Sodium and Potassium ions on the inner and outer surface of cell membranes of neurons. Can you imagine the speed of these impulses? It varies from 290 km/hour in normal humans to 240 km/hr in old age people. So now you find that this soft organ is so  tough to understand.

Trackback URI | Comments RSS