Human Brain, Its Parts and Their Function

What is Human Brain?

Human brain is the most important part of human body. It weighs about 1.5 kg. It contains about 100 billion neurons or nerve cells each of which is connected with a thousand or more other nerve cells, making an extremely complex network of cells and nerve fibers. The brain receives and sends messages to organs and muscles along a network of nerve fibers. These messages are tiny electrical impulses which can whiz along at the speed of up to 100 meters per second. The brain has nerves which directly connect it to the organs of the head, but most nerves are connected to the brain by way of the spinal cord. 

Parts of Brain

Cerebrum

The largest and most complicated part of the human brain is the cerebrum. It receives information from all the sense organs and uses it to control your actions, behavior and speech. The cerebrum is also the part of the brain which we use for thinking, remembering things, solving problems and making decisions. 

Cerebral Hemispheres

The cerebrum has two halves, called cerebral hemispheres, linked by bundles of nerve fibers. Sensation from one side of the body connect to the opposite side of the cerebrum, and movements of one side of the body are controlled by the other side of the cerebrum. The right side of the cerebrum is the most important in artistic and creative tasks, while the left controls understanding, reading and thinking.

Cerebellum

The cerebellum keeps the body balanced and coordinates the muscles during walking, running, cycling and other physical activities. The medulla oblongata controls the breathing and heart beat rate, and maintains the pressure of the blood and the body temperature.   

The Brain Stem

The brain stem, close to the spinal cord, controls the body's automatic activities, such as breathing and digestion. 

The brain needs a great deal of energy to do its work. Although it only weighs about 2.5 percent of the weight of the whole body, the brain uses about one-fifth of all the energy the body produces. Without oxygen, the brain cells are quickly damaged and are unable to repair themselves. After about five minutes without oxygen, the whole brain is dead.