Brain

You brain is as big as your fists side by side. It’s the place where you think, learn, work out problems, remember, feel happy and sad, wonder, worry, have ideas, sleep, and dream.

Yet the brain looks like wrinkly lump of grey-pink jelly! On average, it weighs about1,4 Kilograms. It doesn’t move, but its amazing nerve activity uses up one-fifth of all the energy needed by the body.

The main part of the brain is its bulging, wrinkled upper part, the cerebrum. Different areas of its surface (cerebral cortex) deal with nerve signals to and from different parts of the body. For example, messages from the eyes pass to the lower rear part of the cerebrum, called the visual centre. They are sorted here as the brain cells work out what the eyes are seeing.

There are also areas for touch, hearing, taste and other body processes.

The cerebellum is the rounded, wrinkled part at the back of the brain. It processes messages from the motor centre, sorting and coordinating them in great detail, to send to the body’s hundreds of muscles. This is how we learn skilled, precise movements such as writing, cycling or plating music (or the three), almost without thinking.

The brain stem is the lower part of the brain, where it joins the body’s main nerve, the spinal cord. The brain stem controls basic processes vital for life, like breathing, heartbeat, digesting food and removing wastes.

The brain really does have ‘brain waves’. Every second it receives, sorts and sends millions of the nerve signals. Special pads attached to the head can detect these tiny electrical pulses. They are shown on a screen or paper strip as wavy lines called an EEG, electro-encephalogram.

Source : 100 Things You Should Know about the Human Body