The brain stem sits beneath your cerebrum in front of your cerebellum. It connects the brain to the spinal cord and controls automatic functions such as breathing, digestion, heart rate and blood pressure.

The cerebellum sits at the back of your head, under the cerebrum. It controls coordination and balance.

The cerebrum fills up most of your skull. It is involved in remembering, problem solving, thinking, and feeling. It also controls movement.

Your brain is your most powerful organ, yet weighs only about three pounds. It has a texture similar to firm jelly.

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The whole vessel network includes veins and capillaries in addition to arteries.

With each heartbeat, arteries carry about 20 to 25 percent of your blood to your brain, where billions of cells use about 20 percent of the oxygen and fuel your blood carries.

Your brain is nourished by one of your body's richest networks of blood vessels. When you are thinking hard, your brain may use up to 50 percent of the fuel and oxygen.

Your brain's wrinkled surface is a specialized outer layer of the cerebrum called the cortex. Scientists have "mapped" the cortex by identifying areas strongly linked to certain functions.

Left Brain/Right Brain

Your brain is divided into right and left halves. Experts are not certain how the "left brain" and "right brain" may differ in function. In most people, the language area is chiefly on the left.