The Romantic Doctorover 7 years ago

Facts about the human brain

•The human brain is the largest brain of all vertebrates relative to body size •It weighs about 3.3 lbs. (1.5 kilograms) •The brain makes up about 2 percent of a human's body weight •The cerebrum makes up 85 percent of the brain's weight •It contains about 86 billion nerve cells (neurons) — the "gray matter" •It contains billions of nerve fibers (axons and dendrites) — the "white matter" •These neurons are connected by trillions of connections, or synapses