The Amazing Brain
The brain is a monstrous, beautiful mess. Its billions of nerve cells - called neurons - lie in a tangled web that displays cognitive powers far exceeding any of the silicon machines we have built to mimic it.
William F. Allman in Apprentices of Wonder.
Inside the Neural Network Revolution, 1989.
The human brain is the most amazing and complex organ in this universe. In terms of design, architecture, ability and potential, it remains unmatched in our natural world. From it comes our personality, pleasures, joy, laughter, fears, sorrow, tears, and dreams.
Shaped like a loaf of French bread, it is a crowded chemistry lab, bustling with nonstop neural conversations:
- At birth our brains weigh a little less than 1 pound, and an adult brain weights about 3 pounds. Although the brain only accounts for 2% of our body weight, it consumes 20% of the oxygen that we breathe and 20% of our daily calories.
- The brain is made up of different materials: about 78% is water, about 10% is lipids, 8% protein, 1% carbs, 2% soluble organics, and 1% inorganic salt. Dehydration can affect proper functioning of the brain.
- Fifteen to twenty percent of all blood pumped out of the heart goes directly to the brain. About 3 full soda cans of blood flow through the brain every minute. In that minute the brain will consume 1/5 cup of oxygen from that blood.
- The brain can stay alive for 4 to 6 minutes without oxygen; after that cells begin to die and serious brain damage occurs.
- The energy used by the brain is enough to light a 25-watt bulb.
- More electrical impulses are generated in one day by a single human brain than by all the telephones in the world.
- There are about 100 billion neurons in the human brain, the same number of stars in our galaxy. From the age of 35, about 7000 neurons are lost daily.
- The diameter of an individual brain neuron is 4 microns; 30,000 neurons could fit on the head of a pin.
- Each time you have a new thought or memory, a new brain connection is made between two or more brain cells.
- Each neuron has from 1,000 to 10,000 connections with other neurons, making up to 10 trillion neuron connections possible.
- The left hemisphere of the brain has 186 million more neurons than the right hemisphere (most likely because the left side is where language is stored).
- The slowest speed at which information travels between neurons is one-thousandths of a second, or 260 mph; that’s as "slow" as today’s supercar (the Bugatti EB 16.4 Veyron clocked at 253 mph).
- How much does the human brain think? It is estimated that the human brain produces about 70,000 different thoughts on an average day.
- After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
- Albert Einstein’s brain weighed 1,230 grams (2.71 lbs), significantly less then the human average of 1,300g to 1,400g (3 lbs). He was also believed to have been dyslexic.
- The brain itself is incapable of feeling pain. Once the skull is opened it is possible to operate on the brain with the patient awake.
- Stress over long periods can weaken the brain’s ability to learn and remember.
- The human brain contains 400 miles of blood vessels.
- A living brain is so soft you could cut it with a butter knife.
- Brain imaging studies show that human feelings originate inside the brain.
An interactive infographic by Open Colleges