My Science School

What is a healthy diet for older people?

            It is very important that old people eat fresh food. The elderly need to eat protein, fat and carbohydrate, which form the basis of any healthy diet. They need plenty of fresh fruit and vegetables.           

How can old people keep healthy and mobile?

            Exercise is important because it keeps bones, joints and muscles healthy. You cannot expect an older person to take vigorous exercise, but walking and even swimming help the circulation and keeps the joints supple. If old people are receiving medical treatment, it is important that their doctor advices on the proper level of exercise, to avoid doing any damage to their body.

 

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Can we help old people to have an active life?

            Old people sometimes need to be helped to live their lives to the full. Loneliness is one of the most common features of an old person’s life, particularly if the person has lost a partner. Most people no longer live in large families within one house, and a single older person can feel very isolated. Although they may not be physically strong, almost all older people can and should take exercise.

            Most old people enjoy the company of younger people. Keeping both the mind and body active will help an old person’s general health and wellbeing. Above all, the company of other people is the best tonic they can have.

How long do people live for?

            People are living longer and longer, and most of us can expect to live to the age of 75 years or more we can also expect to be reasonably healthy for almost all of this time. Because so many of the diseases that caused people to die young are now being controlled, and people have a far better standard of living, most of us are living much longer than our ancestors.

            We are also staying much healthier right up until the end of our lives. This means that a growing number of healthy and active older people are working part-time to occupy themselves and to provide an extra income. This activity helps to keeps their minds and bodies active.

            In 1997 a French woman died at the age of 122 years. She was the world’s longest-lived person.

Why do old people get shorter?

            The spine becomes shorter in older people because the pad of cartilage between the bony vertebrae grows thinner. Older people often lose bone in a condition called osteoporosis. This usually affects elderly women, although it can also appear in men. The bone becomes spongy, and when it affects the vertebrae in the spine they may collapse. This causes pain, and also makes the person’s spine shorter and curved. Osteoporosis can be treated with drugs, and a diet containing the mineral calcium can also help. Calcium is plentiful in milk and cheese.

Do people become forgetful in old age?

            It is very common for old people to become forgetful, although many retain perfect memories from long ago.

            Many things can cause forgetfulness. Sometimes the blood supply to the brain is not effective. The brain cells become starved of oxygen and nutrients, leading to dizzy spells and forgetfulness. Dementia is a condition where forgetfulness becomes a serious problems, and the person may not be able to look after himself or herself. Alzheimer’s disease is the most serious form of dementia. For most old people, memories bring great pleasure. Strangely, even though recent events may be forgotten, old people often clearly remember events that took place in their childhood.

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Why do people grow old?

            Ageing is a result of the gradual failure of the body’s cells and organs to replace or repair themselves. This is because there is a limit to the number of times that each cell can divide. As the body’s cells begin to near this limit, the rate at which they divide slows down. Sometimes the new cells that are produced have defects or do not carry out their usual task effectively. Organs can then begin to fail, tissues change in structure, and the chemical reactions that power the body become less efficient.

How does the body change with increasing age?

            Older people are no longer growing, and so they are not as active as they used to be. For this reason they do not need to eat as much, and quite often become thinner. The body loses muscle as well as fat, and sometimes older people become unsteady on their feet.

Why does the skin become wrinkled?

            The skin becomes looser as people age. As skin sags it forms into wrinkles and creases. This happens because the fibres of collagen that normally provide support to the skin become weaker. Smoking and over-exposure to the Sun can make skin more likely to wrinkle.

What is an antibiotic?

                     Antibiotics kill bacteria by interfering with the way in which bacteria reproduce. Antibiotics are produced naturally by many simple plants and even other bacteria. Antibiotics are useful because they seldom have any bad effect on the person taking them. The use of antibiotics has meant that many diseases that were usually fatal can now be cured.

                   Antibiotics work by damaging bacterial reproduction rather than killing the bacteria outright, and so it is important to take the full course of the drug. Often you will feel better within a couple of days of starting treatment, but if you stop too soon the bacteria can recover. When you keep taking the drug, after several days the bacteria die and are cleared away.

 

 

 

How was penicillin discovered?

                        Penicillin was the first antibiotic to be discovered, by Alexander Fleming. He was searching for substances that would kill bacteria when he noticed some mould growing on an experimental dish. The mould killed the colonies of bacteria that were growing around it. Penicillin was extracted from this mould, and its use has saved millions of lives. Many other antibiotics have since been discovered or made artificially.

 

Are all drugs dangerous?

                       People take so-called recreational drugs, such as cannabis and heroin, because of the effect they have on the brain. (These drugs are different from medical drugs that people take when they have an illness or disease.) Recreational drugs can be a danger to health. Some of them make people feel excited and full of energy. Others make them feel sleepy, and some drugs can make people experience imaginary situations. All these drugs cause the brain to malfunction, and if taken regularly they can cause permanent damage to health.

                      Some of these drugs are addictive. This means that they cause changes in the brain that make people crave them, even though the pleasant effects may wear off.

 

 

How do medical drugs work?

                     Many medical drugs work by correcting the chemical reactions within the body that are responsible for disease. For example, insulin injections replace insulin that is not being produced by the pancreas, so sugar can be used properly by the body. In depression and mental illness, drugs can restore the balance of chemicals in the brain. Aspirin is often given to cure a headache, but it can also neutralize the inflammation that causes pain in the joints of people suffering from arthritis.

                       Modern drug research studies the cause of diseases, and then designs molecules that interrupt or reverse the disease process. All drugs cause some unwanted effects, and scientists try to find new drugs that relieve disease without causing further problems.

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Why is smoking harmful?

                             Cigarette smoking is known to be the main cause of lung cancer. It also causes bronchitis, heart disease and other problems with the circulation. Cigarette smoke contains many harmful substances, which are all deposited straight into the lungs. The smoke contains tiny particles of soot that can clog the air passages. The tar in smoke contains substances that can cause cancer. The nicotine in cigarettes is a strong addictive drug that can affect the heart and circulation. However, this addiction can be very difficult to break.

                             The harmful effects of cigarettes may only appear after many years of smoking. However, even when a smoker gives up the habit, it can be years before these health risks are cancelled out.

 

What is health?

                    Being healthy involves far more that simply not being ill. If you feel in good health, your organs will be working properly and you will have the energy to live life to the full. This feeling of wellbeing affects your mind and your body.

How can I keep myself healthy?

                    The environment you live in, your diet and your lifestyle affect your health. Physical fitness is an important part of health, and this means that your heart, lungs, skeleton and muscles all work together smoothly to carry out your daily activities. Fitness involves strength, stamina and suppleness, and you need regular exercise to maintain all these conditions. Careful exercise develops a healthy heart and lungs, and gives you the strength and stamina that allow you to run, cycle and swim. A sensible diet and sufficient sleep also help you to keep healthy.

 

 

 

 

Can the environment harm health?

                    Air pollution is an environmental factor that can damage health. Exhaust fumes from motor vehicles contain substances that can cause asthma and other breathing problems. In hot climates smog can also develop, trapping these air pollutants and making the health risk greater.

 

 

 

 

What causes disease?

                      Many diseases are infections that are caused by bacteria or viruses. Other illnesses are caused by failure of some of the body’s organs or tissues. Sometimes parts of the body wear out or are not replaced properly, but most health problems are caused when the body simply fails to maintain itself. Joints can wear out, causing arthritis, or the digestive system may not work as efficiently, causing various types of stomach upset. Other diseases may be caused by a person’s own lifestyle, for example lack of exercise or poor eating habits. Smoking is now known to be a contributory factor in many diseases.

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What is a photographic memory?

                      A few people have the ability to remember a scene or picture just as though they were looking at a photograph. They can recall all the details in the picture, or remember where a particular word is on a page.

 

 

 

 

 

What is a mnemonic?

                         Although a memory is stored in the brain, sometimes you cannot find the route to retrieve it. The memory remains hidden. Mnemonics are simple tricks developed to help us remember. Often these are in the form of rhymes, which are seldom forgotten, such as ‘Thirty days hath September…’ to remind you of the number of days in each month, Another example is ‘Richard Of York Gave Battle In Vain’ to remind us of the colours of the rainbow. Other people associate the thing they want to remember with something completely unrelated but which sounds similar. Most people developmental tricks of this sort. They can be useful for remembering important facts during exam revision.

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Are there different types of memory?

                        There are three different ways in which memory can be stored. Sensory memory is very brief. It tells you what is happening around you and allows you to move around without bumping into things, Short-term memory lasts for about 30 seconds. It allows you to look up a number in a phone book and dial the number without forgetting it, but after a minute or so it will have vanished. Long-term memory is for things that you have carefully memorized and learned. It may last for years, and some memories can last throughout your life.

 

How do I remember things?

                    Memory is the ability to store things that you experience and learn, ready for future use. Some things are remembered easily, such as a dramatic event in our life. However, more ordinary things need to be rehearsed in the mind several times before they ‘stick’. This is why revision is necessary when studying for an examination.

Can the brain alter to help people to learn?

                            The structure of the brain can alter slightly as you learn new memories and activities. The number of connections between neurones can increase as you learn a repetitive task, making it easier for nerve impulses to travel through and retrieve a memory. This is why once you have learned a task like riding a bike or swimming, you never forget how to do it. You don’t have to think about it at all once you have learned the skills that are needed. Catching a ball is an example of this. Young children cannot coordinate their hands and eyes well enough to catch a ball at first, but after many fumbles they will learn to catch every time.  

Are brain circuits already in place in a newborn baby?

                            Brain circuits are already in place to maintain the body of a newborn baby, but they continue to develop as the child grows. It is not possible for a very young child to learn language because the brain is not sufficiently well developed. All children, in any culture, start to learn a language in several distinct stages as they grow. By the age of two years most children have an extensive vocabulary of several hundred words, and by the age of four years they understand the simpler rules of grammar. For this reason, some scientists suggest that the brain is ‘pre-wired’ for learning language.

Where are memories stored in the brain?

                           Memories are not stored in any one area of the brain. Because the neurones in the brain are connected in a network, parts of memory can be stored in different places. It seems that for short-term memory, things you have seen are stored near the part of the brain that deals with vision, while sounds are stored near the part of the brain dealing with hearing, and so on. Longer-term memories are stored in a small circuit of several connected nerve cells.

Why does relaxing help you to remember?

                         When you struggle to remember something this often seems to make it even harder to recall. When you relax, your brain tends to explore alternative routes to find the lost piece of information without you being totally aware of it. It is rather like finding a different way around a maze. You will usually be thinking about something completely different, when the piece of information you were trying to recall suddenly comes to mind. Even though you were not consciously looking for it, your brain will have been continuing to seek out the information you wanted.

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What is conditioning?

                      A conditioned action is one that becomes automatic after being repeated many times. You become conditioned to feel hungry when you smell cooking, or to feel thirsty when you hear someone pull the ring off a soft drinks can.

 

 

 

 

 

 

 

 

 

 

 

Can a smell bring back a memory?

                        The sense of smell has powerful effects in retrieving memories. Often a smell can suddenly trigger a memory from many years ago. Sounds and tastes do not seem to work in the same way.

 

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Are there special regions on the surface of the cerebrum?

                    A narrow strip across the top of cerebrum, called the motor cortex, is concerned with organizing your movement. Another part of the cerebrum is the sensory cortex, where senses such as touch, vision and hearing are controlled. This part shows the relative importance of some of our senses. A large area of the cerebrum is concerned with the hands, eyes and mouth because they are highly sensitive areas.

 

 

 

 

 

How is the brain protected from damage?

                      The bony cranium that surrounds the brain protects it from blows, but could easily be shaken in an accident. The brain is cushioned by three layers of tough membranes called the meninges. They are filled with liquid in which the brain floats.

 

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Why does the brain have two sides?

                       The cerebrum is divided lengthways into two halves, called cerebral hemispheres. Each side of the brain controls the opposite side of the body. For example, if you move your right leg, the instructions for that movement come from the left side of the brain. The nerve cells that carry messages from the brain cross over at the base of the brain. In most people the left side controls speaking, writing and logical thought, while the right side controls artistic abilities and creative thinking. Most people seem to use one side more than the other. This is why some people seem to be more artistic than others, or are better at scientific and mathematical thinking. Usually the left side of the brain is more dominant as far as movement is concerned, which is why most people are right-handed. About 10 percent of people are left-handed.

How does the brain allow us to make careful movements?

                         Fine movements are possible because the cerebellum filters instructions from other parts of the brain to the muscles. It monitors these instructions and ensures that the muscles work together. The cerebellum is part of the brain that is well understood. Its neurones are arranged in a regular pattern and it has been possible to trace the electrical circuits from one neurone to another. This part of the brain works very much like a computer.

 

 

 

 

 

Which is the oldest part of the brain?

                    The brain stem is sometimes called the oldest, part of the brain. This is because it keeps the whole body alive. Even if the other parts of the brain are destroyed, the brain stem often keeps a person alive for some time.

 

 

 

What are the main parts of the brain?

                            The brain is divided into three main regions each with different functions. The large part at the top is the cerebrum. This is where most of our reasoning, thinking and memory are controlled. The cerebellum is a smaller area at the back of the brain, where accurate movement and coordination are controlled. The brain stem is a small region at the base of the brain where most of our automatic body functions are controlled. It is connected to the spinal cord.

Which part of the brain makes me different from animals?

                           The cerebrum is the part of your brain that gives you your intelligence and emotions. It makes up about 85 percent of the total brain weight of 1.4 kg. In proportion to the size of the human body, it is by far the biggest cerebrum in any living creature. Its grey surface is made up of millions of nerve cells. The white layer beneath is mostly made of the nerve fibres connecting them. The surface of the cerebrum is wrinkled and looks rather like a cabbage.

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What job does the brain do?

                 The brain is the body’s control centre. It coordinates all the messages that pass through the nervous system, giving us the ability to learn, reason and feel. It also controls the body’s automatic functions such as breathing, heartbeat, digestion, growth and blood pressure.

 

 

Does the brain think like a computer?

                       The brain resembles a computer because it has a memory and generates millions of electrical signals. However, it works in quite a different way from a computer.

                      A computer can calculate accurately, but it can only use the information programmed into it. The brain is able to learn and grow in complexity from the day you are born. Unlike most computers, it is able to make decisions without necessarily having all the information that a computer would need. The brain has powers of imagination and reasoning, but computers are only just acquiring these abilities.

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