The Human Brain
The human brain is a very powerful organ. It controls all parts of the body and allows you to think, feel, move your arms and legs and it helps you stay healthy.
The brain looks like a pink sponge and consists of a mass of nerve cells. It is protected by the skull. An adult's brain weighs about 1.5 kilograms.
Main Parts of the Brain
The biggest part of the brain is the cerebrum. It makes up about 85 % of the brain's weight. Its surface has a lot of wrinkles and cracks. The cerebrum is the thinking part of the brain. It controls your muscles and makes them move when you want them to.
When you think hard , try to solve a math problem or draw a picture you use your cerebrum. It is also the area which stores your memory.
The cerebrum has two halves. Some scientists think that the right half helps you think about things like music, colours or shapes. The left half helps you think logically and controls your speech. The right half of the cerebrum controls the left side of your body and the left half controls the right side.
The cerebellum is a lot smaller than the cerebrum and sits at the back of the brain. It's very important because it controls balance, movement and the way your muscles work together.
It allows you to stand on your feet without falling down or lets you balance your weight on a surf– or snowboard.
The brain stem is below the cerebrum and in front of the cerebellum. It connects the brain to your spinal cord. This part of the brain controls the functions your body needs in order to stay alive and it is in charge of things that happen automatically. Breathing, body temperature, pain , hunger and heartbeats are all managed by the brain stem.
It tells your heart to pump more blood when you go jogging and need more oxygen, or it tells your stomach to digest the food that you eat. It sends messages back and forth between your brain and other organs of your body.
The Nervous System
The brain is made up of millions and millions of nerve cells called neurons. Almost all of them are there when you are born but they are not connected with each other. When you learn things as a child the brain starts to create pathways between the neurons. As time goes on things become easier for you to do and you don't have to think about them because you do them automatically.
Injuries , illnesses and other diseases that you may inherit from your parents or grandparents can damage your brain. Disorders that destroy brain cells are very serious because the body cannot replace lost cells.
A stroke occurs when the brain cells do not get enough oxygen , which is transported throughout your body by blood . If this happens the brain can no longer work in the damaged area . Many stroke victims are not able to use a certain side of their body and, very often, they lose the ability to speak clearly. Strokes are often caused by high blood pressure or when arteries become harder. Some stroke victims die, others recover partly.
Brain tumours are caused by the rapid growth of cells. Such fast-growing cells destroy healthy ones. As they grow they create pressure and may damage other areas of the brain. Sometimes tumours can be removed by operations or with drugs
Many diseases that are caused by bacteria or viruses can also do damage to the human brain. One of the most common illnesses is meningitis, a disease that affects the membranes that cover the brain and the spinal cord.
Sometimes the brain of an unborn baby does not develop the way it should. In Down's syndrome there is an extra chromosome that causes mental disorder. In other cases genetic errors cause brain damage in later life. Huntington's disease, for example, occurs mostly during middle age. It leads to jerky movements of the body.
Alzheimer's disease often occurs after the age of 60. Many victims suffer from a loss of memory and they often cannot care for themselves.
Today, modern medicine has ways and methods of looking into the human brain. The EEG ( electroencephalogram ) records the activity in the brain. Computed tomography makes pictures by sending many X-rays through the brain. Magnetic resonance imaging (MRI) uses powerful magnets to show how atoms in your brain change.
What can you do for your brain?
- Eat healthy food
- Don't drink alcohol or smoke cigarettes
- Wear a helmet when you ride a bike, go snowboarding or roller skating. It protects you from head injuries.
- Use your brain by doing a lot of things that forces it to work. Activities like reading, playing music and solving puzzles keep your brain active.
Interesting facts about the brain
- In an unborn baby , the brain is formed much quicker than other organs
- The brain reaches its full weight when you are 6 years old.
- The brain does not feel any pain. As a result doctors can perform operations on people who are conscious.
- Brain cells begin to die if they don't get oxygen for three to five minutes.
- The brain gets 20% of your body's oxygen even though it only makes up 2 % of your weight.
- Everyone's brain has the same features but no brain looks exactly like any other.
Downloadable PDF Text- and Worksheets
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- ability =the power to do something
- activity = something that happens
- affect =to have an effect on ; influence
- allow = let
- area = place
- artery = a tube that carries blood from your heart to the rest of your body
- balance =to spread your weight so that you do not fall
- blood pressure =the force with which blood travels through your body
- breathe = to take air into your lungs and send it out again
- cause =reason for
- cell = the smallest part of a living thing that can exist by itself
- certain =special
- common = very popular
- connect = join together
- conscious = to be awake ; if you are able to see and understand the things around you
- consists of = is made up of
- crack =a line that splits an object apart, but it doesn’t break
- create = make
- damage =destroy, hurt
- destroy =damage
- develop = grow
- digest = to change food that you have eaten into things your body can use
- disease = illness
- disorder = an illness which does not let parts of your body work in the correct way
- drug = here : medicine
- error = mistake
- feature =characteristic, special quality
- force =to make someone or something do something
- functions =job, task, work
- genetic =what you get from your parents
- growth =to get bigger
- in charge of = to control
- inherit = get
- injury = when you are hurt in an accident
- jerky =rough, sudden movements, with many starts and stops
- loss = if you lose something
- manage = control
- membrane = a thin piece of skin that covers or connects parts of your body
- memory = the ability to remember things that have happened
- mental = everything that has to do with your brain
- movement = when you change your position or move from one place to another
- occur = to happen
- oxygen = the gas that is in the air and that we need to survive
- pain = the feeling you have when your body hurts
- partly = not fully
- pathway = many nerves that give information to each other
- pressure =force, weight
- protect =defend, guard
- rapid = fast
- reach = get to
- record = to write down on a machine
- recover = to become healthy again
- remove = to take away
- replace =put back, return
- scientist =a person who is trained in science
- serious = very bad, dangerous
- shape = the form that something has
- skull = the bones of the head
- solve = to find a way to do something
- speech = the ability to speak
- spinal cord = the thick string of nerves that lies in your back . It transports messages to and from your brain
- sponge =soft material that can absorb water; it is used for washing and cleaning
- store = to keep things in a place
- stroke =when an artery with blood suddenly breaks open or is blocked ; when this happens a person may not be able to use some muscles; it can even lead to death
- suffer =to feel pain
- surface =the top part of an object
- victim =here: people who have this illness
- weigh =how heavy something is
- weight =how heavy something is
- wrinkles = lines in your skin
- X-ray = light that goes through a person's body . It can show you pictures of inside organs