The Brain 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 Encyclopedia. ) 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 its 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 ste 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 Encyclopedia. ) 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 Encyclopedia. ) 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 Encyclopedia. ) 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 8 th 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 didnt 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 Croton 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 didnt 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 brain. 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. Augustine 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 didnt even try anymore after Nemesius and St.

Augustine. This happened because everyone accepted Gallons theory and didnt 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 Galen theory, thought that the brain was the center of sensory and muscular activities. Vesalius was right, but didnt 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 1850 s and the 1900 s 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 its not. I learned a lot about the human brain and why its 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.