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a. Brain
The brain is housed inside
the skull. The average
weight of the brain of an -r-

adult is 1.5 kg. It is made up ,,,__
of soft tissue. It is protected
by the thin layer of the
membrane which is known
as the meninges.
Cerebrum, cerebellum, midbrain, pons varolii and medulla oblongata
are the main parts of the brain. Cerebrum is the largest part of the brain
which is located at the top of the head. It is divided into two halves;
the right hemisphere and the left hemisphere. It enables us to think,
remember, and use logic. It also enables us to interpret the situation
or events and take the right decision. It manages the functions of senses
such as sight, sound, smell, taste and touch. Overall, it commands and
coordinates the functions of other organs of the body including the brain.
Cerebellum (little brain) is located under the cerebrum and at the
back of the pons varolii. Its main function is to control and coordinate
muscle inovements such as walking, running, eye movement, and
other physical activities. It helps to maintain the balance and posture of
the body. It sends information and signals it has received to the cerebrum.

Midbrain is located between the cerebrum and pons varolii. It
consists of a nu1nber of nerve cells and fibres. It works as a bridge for
transmitting information between the cerebrum and the spinal cord. It
receives information from the spinal cord and sends it to the cerebrum.
Likewise, it passes com111and from the cerebrum to the spinal cord.

Pons varolii works as a bridge between the midbrain and medulla
oblongata. Infonnation and command transmit through pons varolii
from the cerebrum to the medulla oblongata. The medulla oblongata
is the bottom-most part of the brain. It connects the brain to the spinal
cord. It regulates and controls circulation and respiration. It also
regulates the reflex actions such as quick withdrawal of hands from
a hot item, and sudden blinking when an insect comes very close to
the eyes.

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