Much of the brain's
job involves receiving information from the rest of the body, interpreting that
information, and then guiding the body's response to it. Types of input the
brain interprets include odors, light, sounds, and pain. The brain also helps
perform vital operations such as breathing, maintaining blood pressure, and
The brain is divided into
sections. These sections include the cerebrum, the cerebellum, the diencephalon, and the brain stem.
Each of these parts is
responsible for portions of the brain's overall job. The larger parts are, in
turn, divided into smaller areas that handle smaller portions of the work.
Different areas often share responsibility for the same task.
The cerebrum is the largest part
of the brain. It handles memory,
speech, the senses, emotional response, and more. It is divided into several
sections called lobes. These lobes are the frontal, temporal, parietal, and
occipital; each handles portions of the cerebrum's jobs.
The cerebellum is
below and behind the cerebrum and is attached to the brain stem. It controls
motor function, the body's ability to balance, and its ability to interpret
information sent to the brain by the eyes, ears, and other sensory organs.
The functions the
brain stem governs include respiration, blood pressure, some reflexes, and the
changes that happen in the body during what is called the “fight or flight”
response. The brain stem is also divided into several distinct sections: the
midbrain, pons, and medulla oblongata.
The diencephalon is inside the
cerebrum above the brain stem. Its jobs include sensory function, food intake
control, and the body's ability to sleep. As with the other parts of the brain,
it is divided into sections. These include the thalamus, hypothalamus, and
The brain is protected from
damage by several layers of defenses. Outermost are the bones of the skull.
Beneath the skull are the meninges, a series of sturdy membranes that surround the
brain and spinal cord. Inside the meninges the brain is cushioned by fluid.
Still, the brain can suffer damage, become diseased, or malfunction. These
problems may include cancer, physical injuries such as skull fractures, and
ruptures of blood vessels that supply the brain.