The Human Brain
The brain is made up of very soft and delicate tissues. It is protected from injury by the cranium and layers of membranes called meninges. The brain consists of two layers. The outer layer is called the grey matter and the inner layer is called the white matter. The grey matter is made up of cell bodies of neurons while the white matter consists of nerve fibers..
The brain together with the spinal cord forms the central nervous system. It is connected to other parts of the body by the spinal cord and the peripheral nervous system. The brain acts as controlling and coordinating centre for our responses. It receives impulses from sensory organs, analyses the information received and sends them to effectors organs to bring about a response. The brain can also store information. As a result, our behavior can be modified according to past experiences.
Structure and Functions of the Human Brain
The brain is made up of very soft and delicate tissues. It is protected from injury by the cranium and layers of membranes called meninges. The brain consists of two layers. The outer layer is called the grey matter and the inner layer is called the white matter. The grey matter is made up of cell bodies of neurons while the white matter consists of nerve fibers. The three parts of the human brain are the: a) cerebrum b) cerebellum c) medulla oblongata.
Cerebrum
The cerebrum is also known as the fore-brain. It makes up about 80% of the total weight of the brain. The cerebrum is made up of the right and left hemispheres. The right hemisphere receives impulse from the left side of the body while the left hemisphere receives impulses from the right side of the body. The surface of the cerebrum is folded into grooves to increase its surface area to hold more neurons thus storing more information. It is richly supplied with blood vessels to provide oxygen and food to the neurons. Each hemisphere controls the actions and sensations of the opposite side of the body.
The functions of the cerebrum include: a) controlling voluntary b) receiving and interpreting impulses from sensory organs c) controlling behavior and emotions. The cerebrum is responsible for our self-awareness and also determines our personality.
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The cerebrum is divided into many areas according to their functions: a) areas which control mental activities such as learning, thinking, emotion, analysis, memory and imagination b) sensory areas which receive impulses from sensory organs c) motor areas which coordinate various movements d) areas concerned with taste and smell e) areas concerned with hearing and vision.
Cerebellum
The cerebellum is situated below and behind the cerebrum. The surface of the cerebellum is also folded like the cerebrum. The functions of the cerebellum are: a) controlling and coordinating muscular activities such as walking, running and dancing b) controlling and maintaining body balance and posture. The cerebellum carries out its functions using information from the inner ear, the cerebrum and proprioceptors.
Medulla Oblongata
The medulla oblongata is the smallest part of the brain is situated below the cerebellum. It is the enlarged area of the brain stem which connects involuntary actions such as heartbeat, respiration, peristalsis, swallowing, coughing sneezing and salivating. The medulla oblongata can still help to keep a person alive even when the cerebrum and cerebellum of the brain are injured.
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Voluntary and Involuntary Actions
Voluntary actions are actions that are under the conscious control of the brain. An individual is conscious during voluntary actions. It is usually carried out according to one’s wishes and will. Examples of voluntary actions are dancing, talking, writing and laughing. Most voluntary actions are learnt and can become reflex actions after practice. Involuntary actions are actions that cannot be controlled. They are automatic, do not involve any thinking and are not under conscious control. Involuntary actions are coordinated by the medulla oblongata.
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Effects of Injuries to Specific Parts of the Human Brain
Brain injuries may occur due to: a) accidents which cause head injuries b) diseases caused by bacteria and viruses. When a blood vessel in the brain is blocked or bursts, blood supply to the brain is cut off. Some brain cells may die. This condition is called a stroke and may lead to paralysis or death. Meningitis is a disease caused by viruses or bacteria which attack parts of the brain. The microorganisms cause the inflammation of the meninges. It may cause headaches, fever, vomiting and coma, can lead to death. Injuries to different parts of the brain have different effects on the individual.
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Part of the brain Injured |
Effects on the Individual |
|
Cerebrum |
Cannot think logically, may lose various sensations, may not be able to carry out and voluntary movements |
|
Cerebrum |
May lose sense of balance and body coordination |
|
Medulla Oblongata |
May not able to carry out various involuntary actions and may cause death |
|
Inflammation of the meninges Caused by microorganisms |
May cause headaches, fever, vomiting, coma and death |
|
Blood supply cut off |
May cause strike(s), paralysis and death because brain cells may die due to a lack of oxygen. |
Info Gallery
The human brain makes up only 2% of the body’s total weight but it uses 20% of the body’s volume of oxygen and glucose.
Neurons do not reproduce themselves. The neurons you are born with are all you will ever have. By the time a person is 50 years old, about 10% of his or her neurons would have died.
Magnetic Resonance Imaging (MRI) is a technique used to scan the brain to locate the areas of the brain damage, brain disease or unusual brain activity. This is not possible with x-rays as they cannot show brain tissues.
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34 Responses to “The Human Brain”
On June 22, 2009 at 4:24 am
Wow, very informative and good article. I wondered why my brain never stops sometimes.. lol good job again
On June 22, 2009 at 5:03 am
Really nice job, that piece of meat that brought us so much fuzz, this internet hype, blogging, triond and our hardship in earning a dime per gigabyte of publications. But let us look at it on the brighter side when it bears fruit…
On June 22, 2009 at 6:14 am
Interesting. Such an ugly part of the body, with so much power.
On June 22, 2009 at 6:49 am
Very good article!
On June 22, 2009 at 6:55 am
A very informative and beautifully illustrated article. I always learn a lot from your articles.
Christine
On June 22, 2009 at 7:18 am
Very well written.
On June 22, 2009 at 10:20 am
Great informativre article.
On June 22, 2009 at 10:51 am
Great article, liked it!
On June 22, 2009 at 10:57 am
Very Informative and a well researched article
On June 22, 2009 at 12:30 pm
I continue to learn from you well done posts. TX
On June 22, 2009 at 12:39 pm
Our brain is amazing!
Excellent information about our brain.
On June 22, 2009 at 1:23 pm
Excellent article, friend!
On June 22, 2009 at 1:25 pm
Excellent article! Now if I could only find the \”off\” switch!LOL!
On June 22, 2009 at 1:34 pm
great article well written!!
On June 22, 2009 at 2:12 pm
Brainy Stuff!
Loved it.
On June 22, 2009 at 2:43 pm
Wonderful, wonderful article. Absolute research article! Thank you! Liz
On June 22, 2009 at 3:25 pm
Where can I get one of these amazing things from, Mr Ghaz?
On June 22, 2009 at 4:38 pm
nice informative post,nice learning from you sir!
On June 22, 2009 at 7:48 pm
Great work as usual.
On June 22, 2009 at 8:29 pm
Hey there, this is the first of your written work I’ve had the pleasure of reading… it was nicely presented and easy to follow. Thank U
On June 22, 2009 at 9:33 pm
Our brains are so amazing. An excellent rad.
On June 22, 2009 at 10:00 pm
Completed explanation,well done.
On June 22, 2009 at 10:06 pm
Thanks for a well-written piece that uses pictures to great advantage.
Inna
On June 22, 2009 at 11:30 pm
very informative
Thanks for sharing
On June 23, 2009 at 5:55 am
Fascinating article, I learned a lot, the human brain is so complex. Well researched and well written as always.
On June 23, 2009 at 1:58 pm
I like this.
On June 23, 2009 at 2:00 pm
I feel smarter already!
On June 24, 2009 at 9:43 am
Great article Mr Ghaz!
On June 24, 2009 at 10:27 pm
this is an amazing post. very very informative
On June 25, 2009 at 7:21 am
Interesting subject, and very informative..
On June 26, 2009 at 11:40 pm
“Human Brain”..:: Very interesting topics..nice read as always..Thank You so much for this wonderful lesson.
On June 28, 2009 at 8:48 pm
Interesting facts. Very well written too.
On June 28, 2009 at 8:55 pm
I enjoy reading about such a complex creation as the brain…nice job.
On July 9, 2009 at 3:35 am
i learned a lot from you today… excellent job!
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