The Brain

The Brain

Physical Facts

The adult human brain weights about 3 pounds and the cerebrum accounts for about 85% of the brain. The brain is composed of 40% grey and 60% white matter. The grey matter is made up of about 100 billion neurons that gather and transmit signals while the white matter is made of dendrites and axons that the neurons use to transmit signals. The brain is composed of about 75% water and is the fattiest organ in the body, consisting of a minimum of 60% fat. Humans have the largest brain to body ratio of any animal, and the blood vessels in the brain, if stretched end-to-end, would be about 100,000 miles long.  The neocortex, or language centre of the brain, comprises about 76% of the organ.

 

The Developing Brain

Brain development begins very early in the life of a fetus. The brain grows at a rate of about a quarter million neurons per minute in the first trimester, with brain growth continuing through age 18. The brain of a new born baby triples in size during the first year. The amount of brain stimulation a child receives can affect brain growth by as much as 25%. If continued mental activity takes place, new neurons will develop throughout the life of a brain.

Brain Function

Brains use about 20% of the total blood and 20% of the total oxygen that is circulating through the body at any given time. If blood supply to the brain is cut off for more than 8 to 10 seconds, loss of consciousness will occur, yet the human brain can survive for between 4 and 6 minutes without any oxygen. The information processing speed of the human brain can reach up to 120 meters per second, and in a waking state can generate 10 - 23 watts of energy.

The brain is all this and more, providing us with the ability to bond socially with other humans and giving us the facilities for the creativity that makes us the innovators of the animal kingdom.

The Size of the Human Brain

In terms of weight, the average adult human brain weighs in at 1300 to 1400 grams or around 3 pounds.

In terms of length, the average brain is around 15 centimetres long.

For comparison, a new born human baby's brain weighs approximately 350 to 400 grams or three-quarters of a pound.

Men tend to have bigger brains than women. After taking overall body weight into account, men's brains tend to be approximately 100 grams larger than women.

In women, parts of the frontal lobe and limbic cortex (areas associated with problem-solving and emotional regulation) tend to be bigger than those of men.

In men, the parietal cortex (associated with the perception of space) and amygdala (involved in the processing of memory and emotional responses) tend to be larger than those in women.

Neurons are the structures that serve as building blocks of the brain and nervous system. They transmit and carry information, allowing different parts of the brain to communicate with one another as well as allowing the brain to communicate with various parts of the body. Researchers currently estimate that there are around 86 billion neurons in the human brain.

You must be thinking that the brain cannot be about 100,000 miles long. So, I found an answer:

How long is the human brain?

 

Around 15 centimetres is the Size of the Human Brain

In terms of length, the average brain is around 15 centimetres long.

 

But If stretched out it would cover a whole tennis court.