“

Though the three pounds represent only 2% of the body weight of 150-pound person, the quartful of brain is so metabolically active that it uses 20% of the oxygen we take in through our lungs. To supply this much oxygen requires a high flow of blood. Fully 15% of the blood propelled into the aorta with each contraction of the left ventricle is transported directly to the brain. Not only does the brain demand a large proportion of the body’s blood and oxygen, but it also begins its life with an equivalent share, or even more, of genes. Of the total of about 50,000 to 100,000 genes in Homo sapiens, some 30000 code for one or another aspect of the brain. Clearly, a huge amount of genetic information is required to operate the human brain…From all of this emerges the brain’s overarching responsibility – it is the chief means by which the body’ activities are coordinated and governed.

”

Brain consists of 100 billion neurons

|

as many stars as there are in the Milky Way galaxy