The Brain
If the human heart is the engine that powers the body, then the brain is the central computer, controlling nearly every single aspect of the human body’s functions. This organ controls body movement, communication and the analysis and storage of information, among other functions. It is the most powerful organ in the human body, yet it weighs roughly only three pounds, or about 2% of the human body’s weight.
The human brain consists of a mix of gray matter (which makes up about 40% of the brain’s composition) and white matter (which makes up the remaining 60%). Both the brain and spinal cord are protected by a covering of dura matter, a tough membrane, and are surrounded by cerebrospinal fluid in order to cushion both from shock. The human brain can be broken down into three parts. The cerebrum, which takes up the vast majority of space in the skull cavity, handles memory, problem solving, thought and feeling. The cerebellum is located near the back of the skull and controls coordination and balance. The brain stem is located in front of the cerebellum and connects the cerebrum, along with the rest of the brain, to the spinal cord. Together, the brain and spinal cord make up the central nervous system, which distributes electro-chemical signals along the nerves of the body that are translated to both voluntary movements and functions, as well as involuntary movements such as breathing, digestion and heart rate.
Nourishment and the continuous flow of oxygen are very important for the brain to remain functional. Underscoring this importance is the fact that the brain uses about 20% of the oxygen supply and blood flow within the body. If this supply of oxygen and blood is cut off for longer than 3 to 5 minutes, brain cells will begin to die off.
