The Brain Essay, Research Paper
Can you image a hunk of pinkish-gray tissue the size of your hand that
is controlling your entire body? This organ in your body is called the brain.
The brain is not the largest organ but is the most complex organ in your body.
(Metos, 1990, p. 10 ) When you think of the brain do you think of the control
center of movement, sleep, hunger, thirst, and virtually every other vital
activity necessary to survive? Or do you think of the brain as the organ that
controls emotions including, hate, love, fear, sadness, mourning, ect.? I really
doubt you would think of that unless you were an anthropologist, a scientist
who studies humans? ( Funk & Wagnalls Corporation, 1995, Encarta
As a matter of fact, the brain weights about 1.3 kilograms or about 3
pounds, that is in males, because there thick headed, but in females it weights
about 10% less and contains 10 to 15 billion nerve cells. ( Metos,1990, pg.
10. ) These nerve cells are all linked together, they are responsible for the
control of all the mental functions. Also from the outside of the human brain,
which I doubt any of us will ever see in person, looks like it?s divided into
three parts, which it is, the first part is the cerebrum, the second part is the
cerebellum, and the last part is the brain stem.
The three parts of the brain are very complex and have many little parts
in them. The first part of the human brain is the cerebrum and is the largest
part. It weighs about 85% of the 3 pounds. The second part of the human
brain is the cerebellum, which is in the posterior, or the hind part of the brain.
The cerebellum is the center of which reflex, for coordination. The third part
is the most complex, the brain stem is made up of six different parts. The first
part of the brain stem is the thalamus, which lies in the middle of the brain.
This controls all sensory input to the brain, except for smell, connected to the
thalamus is the hypothalamus which lies in the middle at the base of the brain.
This part of the brain stem controls the body functions that are necessary to
survive: eating, drinking, temperature regulation, sleep, emotional behavior,
and sexual activity. The third part of the brain stem is the midbrain, which is
explanatory. The forth part is the pons, which is located between the medulla
and the midbrain, and is directly in front of the cerebellum. The fifth part of
the brain stem is the medulla, which is between the spinal cord and the pons.
This sections looks like a pyramid shaped structure and controls the center of
cardiac vasoconstriction and respiratory functions, also the reflex activities,
including vomiting. If you damage this part of your brain stem it will cause
immediate death. The sixth and final part of the brain stem is the limbic
system. The limbic system is portions of the thalamus, hypothalamus,
hippocampal formation, amygdala, caudate nucleus, septum, and the
mesencephalon. ( Funk & Wagnalls Corporation, 1995, Encarta
What do you think could kill you , a physical injury or a complex
chemical imbalance to the brain? Well, neither one of them could hurt you as
bad as a Brain Disorder! Brain disorders are very serious, they can kill you
or give you other serious problems that could cause your body to breakdown.
For example, if you get a blow to the head you might be dizzy or maybe make
you unconscious for a minute or two but if the blow is more serious you could
possibly go into a concussion which would leave no permanent damage
maybe just a little memory loss. ( Funk & Wagnalls, 1995, Encarta
Speaking of memory loss, memory lose is natural in humans. For
example on this T.V. Show I saw that a 25, and 76 year old man all have
different ranges in memory. Your probably thinking that the older man, who
is 76 years old had the least memory, well, your right and the 25 year old had
the most memory, but they also took a test on vocabulary and the man at the
age of 76 got a score of 20 out of 25 words asked. The 25 year old man got a
score of 15 out of 25 words asked to him, so as you can see the older man
has the least memory loss but is more educated. ( 20/20, on 1-18-98 from
A.B.C. Channel 7 )
Anyway, back to brain disorders, if the blow is much more severe,
dizziness, paralysis, or even temporary blindness may occur. That will
depend on the area of the brain affected. A tumor, you could get a tumor
when some abnormal growth of healthy brain tissue occurs. If this tumor is
located near the surface, it could be removed by surgery to the brain, but if
your not so lucky and the tumor is deeper into the brain it is often treated by
radiation or cooling techniques. ( Funk & Wagnalls, 1995, Encarta
If you get a brain stem injury in the upper part of the brain stem the
symptoms might be: lose of appetite, with an extreme drop in body weight, an
increase in appetite, heading to obesity, extraordinary thirst with excessive
urination, failure in body temperature, which is going to make your body
temperature rise or get lower then it already is and finally uncontrolled anger
or aggression. ( Funk & Wagnalls, 1995, Encarta Encyclopedia. )
If you have what is called a apoplexy or a stoke you could be in big,
big trouble. A stroke occurs when a major artery in the brain is blocked.
When this happens a thrombus occurs, in 8th grade terms a blood clot occurs.
The blood clot comes along when a blood vessel ruptures and bleeding occurs
causing a blood clot. When the blood supply to a small part of the brain is
stopped the cells in that part of the brain die, which causes a function lose to
that area of the brain affected. When a one-sided paralysis or stoke occurs
one side of your body opposite the hemisphere of the brain affected may
make sensory lose. This is called a massive stroke. Those are only a few
injuries or damages that can almost ruin your life and they all happen in this 3
pound hunk of pinkish-gray tissue called your brain. ( Berger, 1983, pg. 102
& Funk & Wagnalls, 1995, Encarta Encyclopedia)
A long time ago no one knew about the brain, they didn?t even know
that the single- celled amoeba has a sensing system that helps it avoid harmful
stimuli. However, over a long process of evolution the development of the
brain in higher order primates, humans, monkeys, ect., were founded to have
a very complex and not understandable to the normal human mind.
Vertebrates, animals with a backbone, however, fish, reptiles, and birds also,
have the same three basic divisions as humans: Cerebrum, Cerebellum, and
the Brain Stem.
The history of the brain is not so complicated as you think it is. The
brain was discovered by many people but the first man to realize that the
heart is not the center of intelligence and the brain is was Alcmaeon of
Croton. Alcmaeon of Crotan was a famous Greek physician. But even
before Alcmaeon there where the Egyptian physicians who operated on
patients with the brain or skull damage, and they didn?t know or were very
unsure of the relationship between the brain and intelligence. In other words
they could have destroyed ones life if they touched the wrong part of the
The most important men in the history of the brain, in my opinion, are:
Galen another famous Greek physician, from the second century A.D., He
described the working of the body as best as he knew it. The role of the heart
and intelligence, however Galen was somewhat unsure of their relationship.
In the forth century, Nemesius and St. Augutine announced the cell doctrine,
in my words, each cavity, or ventricle, of the heart is responsible for human
intelligence. They said that the first cell of the heart is controlling common or
most used sense and imagination; the second is controlling thought, reason,
and judgment; and the third is for housing memory. Well, at least they were
right about the three sections but not in the heart but in the brain. For the next
sixteen centuries this prediction or misconception continued about the heart
being the center of the thought, but the thing that gets me is that they didn?t
even try anymore after Nemesius and St. Augustine. This happened because
everyone accepted Galon?s theory and didn?t even try to experiment, but
there was a man who believed different. This brave man, who I
acknowledge, is Vesalius, the great anatomist of the Renaissance. Vesalius,
whom believed Galens theory, thought that the brain was the center of
sensory and muscular activities. Vesalius was right, but didn?t know it.
Then finally in 1854, when everyone finally believed that Vesalius was
right that the brain was the center of sensory and muscular activities, the first
picture of the brain was taken. Between 1850s and the 1900s the idea of
modern neurology was set, also the science of the nervous system, especially
in France, Germany, and England. Soon after that the scientist had
discovered localized functions of the cortex, the surface layer of the brain.
( Metos, 1990, p. 14-16. )
In conclusion, the brain is very complex if you want it to be but it?s
not. I learned a lot about the human brain and why it?s important to take care
of this hunk of pinkish-gray tissue that controls your every move and thought.
I do think this tissue is such a very complex one. I mean, there are more
complicated organs in your body, but this is probably the most interesting. I
actually enjoyed having to do a research paper because it was on something I
enjoy learning about, the Brain.