The Brain 2 Essay, Research Paper

The Human Brain

The human body is divided into many different parts called

organs. All of the parts are controlled by an organ called the

brain, which is located in the head. The brain weighs about 2.75

pounds, and has a whitish-pink appearance. The brain is made up

of many cells, and is the control centre of the body. The brain

flashes messages out to all the other parts of the body. The

messages travel in very fine threads called nerves. The nerves

and the brain make up a system somewhat like telephone poles

carrying wires across the city. This is called the nervous

system.

The nerves in the body don’t just send messages from the

brain to the organs, but also send messages from the eyes, ears,

skin and other organs back to your brain. Some nerves are linked

directly to the brain. Others have to reach the brain through a

sort of power line down the back, called the spinal cord. The

brain and spinal cord make up the central nervous system.

The brain doesn’t just control your organs, but also can

think and remember. That part of the brain is called the mind.

PROTECTING THE BRAIN

Twenty-eight bones make up the skull. Eight of these bones

are interlocking plates. These plates form the cranium. The

cranium provides maximum protection with minimum weight, the

ideal combination. The other twenty bones make up the face, jaw

and other parts of the skull.

Another way the brain keeps it self safe is by keeping

itself in liquid. Nearly one fifth of the blood pumped by the

heart is sent to the brain. The brain then sends the blood

through an intricate network of blood vessels to where the blood

is needed. Specialized blood vessels called choroid plexuses

produce a protective cerebrospinal fluid. This fluid is what the

brain literally floats in.

A third protective measure taken by the brain is called the

blood brain barrier. This barrier consists of a network of

unique capillaries. These capillaries are filters for harmful

chemicals carried by the blood, but do allow oxygen, water and

glucose to enter the brain.

THE DIFFERENT SECTIONS OF THE BRAIN

The brain is divided into three main sections. The area at

the front of the brain is the largest. Most of it is known as

the cerebrum. It controls all of the movements that you have to

think about, thought and memory. The cerebrum is split in two

different sections, the right half and the left half.

The outer layer of the cerebrum is called the cortex. It is

mainly made up of cell bodies of neurons called grey matter.

Most of the work the brain does is done in the cortex. It is

very wrinkled and has many folds. The wrinkles and folds give

the cortex a large surface area, even though it is squeezed up to

fit in the skull.

The extra surface area gives the cerebrum more area to work.

Inside the cortex, the cerebrum is largely made up of white

matter. White matter is tissue made only of nerve fibres.

The middle region is deep inside the brain. It’s chief

purpose is to connect the front and the back of the brain

together. It acts as a “switchboard”, keeping the parts of your

brain in touch with each other.

The back area of the brain is divided into three different

parts. The pons is a band of nerve fibres which link the back of

the brain to the middle. The cerebellum sees to it that all the

parts of your body work as a team. It also makes sure you keep

your balance.

The medulla is low down at the back of your head. It links

the brain to the top of the spinal cord. The medulla controls

the way your heart pumps blood through your body. It also looks

after your breathing and helps you digest food.

THE DIFFERENT PARTS OF THE BRAIN

THE BRAINSTEM:

The brainstem is one of the oldest parts of the brain. It

controls such functions as breathing, blood pressure, swallowing

and heart rate.

THE HYPOTHALMUS:

This part of the brain is located directly above the brain

stem. The hypothalmus controls basic drives like hunger and sex

and as well as our response to threat and danger. The

hypothalmus also controls the pituitary.

THE PITUITARY:

The pituitary produces hormones such as testosterone that

circulate through out the body.

THE THALAMUS:

The thalamus is like a relay area; it receives messages from

lower brain areas such as the brainstem and hypothalmus and sends

them to the two brain hemispheres. The thalamus is located in

between above the lower brain and under the two hemispheres.

THE DIFFERENT SECTIONS OF THE BRAIN:

Most of the above mentioned parts of the brain were produced

early in evolution but the higher mammals especially humans went

on to produce a sort of “thinking cap” on top of these parts.

This “thinking cap” was divided into two different parts, the

left hemisphere and the right hemisphere.

If the left side of your brain is more developed like most

people’s are, you are right handed. On the other hand if the

right side of your brain is more developed, then you will be left

handed. The right side of your brain is more artistic and

emotional while the left side of your brain is your “common

sense” and practical side, such as figuring out math and logic

problems.

THE CEREBELLUM:

One of the most important part of the Human brain is the

cerebellum. The cerebellum is involved with the more complex

functions of the brain and sometimes is even referred to as “the

brain within the brain”. The cerebellum acts as a control and

coordination centre for movement.

The cerebellum carries small “programs” that have been

previously learned. For example, how to write, move, run and

jump are all previously learned activities that the brain

recorded and can playback when needed. Every time you practice,

the brain rewrites the program and makes it better.

You may have heard the saying “practice makes perfect”.

Well this saying is not entirely true; another way of

“practising” is just to imagine what you wish to do. Since the

cerebellum can’t actually feel, it will think that you are doing

what your imagining and respond by rewriting it’s previous

program and carrying out any other actions needed for that

function. This is one why to explain wet dreams.

THE CEREBRAL CORTEX:

The cerebral cortex makes up the top of the two hemispheres

of the brain. The cortex is a sheet of greyish matter which

produces our thoughts, language and plans. It also controls our

sensations and voluntary movements, stores our memories and gives

us the ability to imagine, in short it’s what makes humans,

humans.

IN THE FUTURE

Today many experiments are being conducted that may be break

through’s for the future. For instance “brain grafting” is one

procedure that may be used in the future. Brain grafting is to

transplant a very thin layer of brain skin from one person to

another. This would result in control of parkinson’s disease and

other seizure related diseases.

Another radical idea that has already been successfully been

tried on rhesus monkey’s is, brain transplants. The ethics and

legal problems for such a transplant would probably never let

this operation be performed on humans. This is because the

person would not be the same, would not have the same memories or

the same abilities that the host body had had.

The last idea of the future that we will list is called

“artificial hearing and seeing”. Artificial seeing is achieved

by planting sixty-four small electrodes in front of the visual

cortex of the brain. The electrodes are connected to a small

camera that is some where on the person’s ear. A computer is

attached to the camera. The computer sends the images from the

camera directly to the implanted electrodes. They flash as the

picture from the camera, thus enabling the person to somewhat

see.

Artificial hearing is much more complicated then artificial

seeing. First a electrodes must be planted in the brain. Then

through a microphone a computer produces electrical pulses that

are then sent to the electrodes in the brain.

But as of yet these procedures are not practical first

because of the size of the computer, it cannot be taken out of

the laboratory second the cost of the package and third the risks

involved.

CONCLUSION

After all of the work and research that we have done it is

very evident to us that the brain is one of the most wondrous

organs that humans could have. It guides us through almost every

second of our life. Even after exploring vast and distant sky’s

to the microorganisms that exist today, the brain has never

ceased to amaze us and probably never will.

BIBLIOGRAPHY

1. The Brain and Nervous System by Lambert, Mark

copyright Macmillan Education, 1988

2. The Brain and Nervous System by Parker, Steve

copyright Franklin Watts, 1990

3. Encyclopedia Britannica by Britannica, Encyclopedia Inc.

copyright Encyclopedia Britannica Inc., 1986

4. The Incredible Machine by Geographic, National Society

copyright Geographic, National Society, 1992