Inside our
heads, there is an amazing organ regulating all activities done by our body. This
organ is brain. Our brain is just like a gigantic-telephone center office with
millions of telephone networks. One of its functions is to ensure that a
message has been delivered to the right muscles so that a response could be
provided. It is referred as coordination. Furthermore, the brain is also
responsible for thinking, memory, and intelligence. The brain is also responsible
for emotion.
The brain is
the control center of all life activities. The brain is protected by brain
membrane referred as meninges. The meninges consist of three layers. They
are dura mater, arachnoid, and pia mater. The dura mater is the outer
layer and attached to the skull bone. Beneath it, there is the arachnoid, which
is a delicate net membrane. Right beneath the arachnoid, there is a pia mater
that is a fat membrane attached to the brain surface.
The human
brain is divided into several parts, namely forebrain, midbrain,
and hindbrain.
1)
Forebrain (Diencephalon)
The forebrain consist of several parts, namely cerebrum, corpus callosum,
and hypothalamus. The cerebrum has folded surface. Its outer part is grey in
color since it consist of nervous cell body. The inner part, however, is white
since it consist of axon and dendrites. The cerebrum is divided into two
hemisphere, those are left and right hemisphere. In between the two, there
corpus callosum that allows the left hemisphere to manage the right-part
organs, as well as the right hemisphere to manage the left-part organs. The cerebrum
functions to gather the information sent by the sensory nerves. Afterwards, the
cerebrum processes and provides response to the information. Since the kinds of
information sent in the cerebrum in quite different, the brain, therefore, is
divided into two parts, namely occipital lobe (rear end) as the center of
sight, temporal lobe (lateral) as the center of hearing, parietal lobe (middle)
as the center of skin and muscle’s works, and frontal lobe (front and rear end)
as the center of intelligence and development.
The hypothalamus is the controlling
center of body homeostasis, such as body temperature and osmoregulation. The hypothalamus
also the center for emotion and aggressive feeling, as well as for
psychosomatic influence.
2)
Midbrain (Mesencephalon)
The midbrain is the optic lobe. This lobe serves an eye and hearing
reflex center. The work of the midbrain to regulate the reflex of narrowing
pupil is an example of this lobe’s function.
3)
Hindbrain
The hindbrain
is divided into two parts, they are cerebellum and medulla oblongata. The cerebellum
has function as the center of balance and muscle coordination. The medulla
oblongata much contains ganglions to control the physiological reflex motion. The
medulla oblongata is also for the control of heartbeat and blood pressure. The cerebellum
and medulla oblongata are interrelated by (pons varoli). This organ has
functions as respiratory center.