Ch. 9 Factors Affecting Human Health

• Health

  A state of complete physical, mental and social well-being

  Health is not just the absence of disease or sickness. In general, it can be considered as:

  • Physical (dealing with the body)
  • Mental (dealing with the mind)
• Single-Gene Disorders - Cystic Fibrosis (CF)


  • an inherited condition caused by a single gene, so it is known as a single gene disorder
  • the dominant version of the gene (N) causes the formation of normal mucus in the breathing system
  • the recessive version (n) causes the production of thick, sticky mucus, which leads to infections of the breathing system
  • it also affects the intestines
  • people can have 3 different genetic combinations with respect to CF:
  • NN = normal mucus
  • Nn = normal mucus
  • nn = cystic fibrosis
• Other single-gene disorders

  1. Sickle cell anaemia: in which red blood cells are wrongly shaped
  2. Coeliac disease: the inability to process gluten, which is found in wheat
  3. Huntington’s: in which nerve cells die, which affects movement
  4. Haemophilia: the inability to form blood clots
• Multi-Gene Disorders - Cancer

  • The term given to a range of conditions (about 200) in which cells lose control of how fast they divide and for how long they divide
  • this causes uncontrolled, rapid growth of cells
  • Cancer usually requires a number of genes to change (it is a multi-gene disorder)
  • some people are born with one or more of these alterations already in place
  • they are more likely to get cancer
• Factors that speed up the risk of the alteration genes

  1. Genetics (as mentioned)
  2. Ultraviolet radiation (e.g. sunlight or sun beds) or excess x-rays
  3. Diet (e.g. too much red meat and lack of fruit and vegetables)
  4. Being overweight
  5. Viruses
  6. Smoking
  7. Lack of physical activity
  8. Problems with white blood cells that normally should prevent cancer
• Other multi-gene disorders

  • Heart disease
  • High blood pressure
  • Alzheimer’s disease
  • Arthritis
  • Diabetes
  • Obesity
  • in addition, some inherited disorders are caused by having an extra or missing chromosome. An example of this type is Down Syndrome (which results in altered mental and physical development)
• Nutrition

  • nutrition is how an organism gets its food
  • all living things need food
  • plants make their own food
  • animals take in food when they eat other plants or animals
• Food is needed to:

  1. Supply living things with energy
  2. Allow them to grow and repair damaged body parts
  3. Prevent them from getting diseases

  • humans must ensure that they take in the correct types of food
  • these foods must also be eaten in the correct amounts
  • we do this by eating a balanced diet
• Balanced diet

  • contains the right amounts of each of the six different types (constituents) of food
  • water is also essential for a balanced diet
• The Functions and Sources of the Parts of a Balanced Diet

  
• Failure to eat a balanced diet results in a person being malnourished and unhealthy. For example:

  • Too many high-energy foods may cause a person to be overweight or obese
  • Not enough energy in a diet may cause a person to be tired and sluggish
  • lack of fibre may result in constipation (and may increase the risk of bowel cancer)
• Food Pyramid


  • Fruits and vegetables
  • Cereals, bread, rice and potatoes
  • Dairy products
  • Meat and fish
  • Fats and spreads
  • Other types of food
• Food Pyramid pt. 2

  • In order to maintain a balanced diet it is necessary to eat different amounts of each food group.
  • The number of servings of each food group that we should eat each day is given in a food pyramid
  • Foods at the top of the food pyramid do not contain minerals or vitamins. They should be eaten rarely as they are high in fats and cause people to be overweight. They also lead to heart conditions and may cause diabetes.
• The amount and type of food needed by each person varies according to factors, such as:

  • Age (younger people need more food than older people)
  • Gender (males need more food than females)
  • Activity levels (active people need more food than inactive people)
  • Health (sick people need smaller portions and softer food)
  • Occupation (active people need more food than inactive people).
• Energy

  • the amount of energy in a food is known as its energy value
  • different foods contain different amounts of energy
  • energy is measured in units called Joules (J)
  • however, the normal unit used for the energy value of food is kilojoules per gram (kJ/g)
• Energy Value

  • in general, carbohydrates and proteins have the same energy values, whereas fats have more than twice the energy value of the other two
  • although carbohydrates and proteins have the same energy values, the human body uses protein for energy only when it is close to starvation
  • This prevents the body from digesting its own body parts, such as muscles and the heart

  
• Eating too much food

  • eating too much food means that the surplus food is converted to fat and stored in the body
  • This leads to problems such as becoming overweight or obese (which means severely overweight)
  • in turn, this can lead to:

  1. increased risk of heart disease
  2. High blood pressure
  3. Diabetes (high blood sugar concentration)
  4. Gallstones (which prevent bile reaching the small intestine)
  5. Breathing difficulties
  6. Some forms of cancer
• Eating too little food

  • eating less food than the body needs, results in weight loss
  • in addition it causes:

  1. Mood swings
  2. Depression
  3. Inability to think clearly
  4. Heart and circulatory problems
  5. Low blood pressure
  6. Reproductive problems
  7. Weak bones
• Lifestyle Choices that Affect Health

  • Diet
  • Exercise
  • Smoking
  • Drink and drugs
  • Sleep
  • Work/life balance
• Smoking

  Smoking is bad for our health. This fact is indicated by the health warning printed on all packets of cigarettes. In addition, smoking is banned in an increasing number of locations and advertisements for cigarettes are strictly controlled.
• Smoke

  • Clogs up the tiny hairs in the nose
  • Allows more dirt particles to enter the lungs
• Smoke irritates the nose and bronchioles

  1. Increased mucus formation

  2. Leads to "smoker's cough"
• Smoking

  Increases the risk of getting lung cancer and other cancers
• Gases in cigarette smoke

  • Enter the blood
  • Reduce the ability of the blood to carry oxygen
  • Heart must pump harder and faster
  • Strains the heart
  • Often leads to heart attacks
• Pregnant woman smokes

  • Chemicals in her blood will enter the baby's body
  • Can affect the development of the baby
• Smoking results in increased lung infections such as pneumonia and bronchitis
• Exercise


  • Regular exercise has many benefits. This exercise might be organised, e.g. in terms of a sport or training or working out in a gym.
  • However, it can also be informal and carried out as part of our lifestyle. For example, walking or cycling to and from school and using the stairs instead of taking a lift are valid forms of exercise.
• Suggested amount of exercise

  • Adults need at least 30 minutes of moderate activity (such as fast walking or cycling) a day on at least 5 days a week.
  • Children need at least 60 minutes of moderate to vigorous activity (such as jogging, running, fast cycling or very active sport) on 7 days a week.
• Benefits of Exercise


  • Helps with weight loss if needed, and prevents weight gain.
  • Reduces the risk of developing conditions such as stroke, heart attack, diabetes, depression, some cancers and arthritis.
  • Increases energy. Regular exercise improves the efficiency of our lungs, heart and blood vessels, which gives us more energy.
  • Improves mood. Physical activity stimulates many brain chemicals that cause us to be happier and more relaxed. It also improves our appearance, confidence and self-esteem.
  • Improves sleep, by helping us fall asleep and stay asleep.
• Alcohol

  • it is illegal for anyone under the age of 18 in Ireland to purchase alcohol
  • there are many problems caused by alcohol
• Alcohol - Problems

  • It is a depressant (it slows down the working of the brain). This can result in altering our emotions, perceptions, vision, hearing and movement.
• Alcohol - Problems

  • It is a toxic substance. This means that it causes us to feel sick, lose co-ordination, stagger, slur our speech and slow our reaction times.
• Alcohol - Problems

  • It changes our mood. Some people become more friendly and talkative, but some people become aggressive and angry.
• Alcohol - Problems

  • Large amounts of alcohol taken in a short period of time may result in alcohol poisoning. This may result in vomiting, extreme sleepiness, loss of consciousness and even death.
  • It is addictive. Anyone who takes alcohol may become dependent on it.
• Drugs

  The effects of drugs depend on:

  • The type of drug
  • The amount of the drug
  • The size of the person
  • How often it is taken
  • How fast it gets to the brain
  • What other drugs, substances or food are taken the same time
  • some drugs can have serious effects on our physical and mental health and are illegal
• Sleep

  In general, young people need more sleep than adults. Most young people need about eight hours' sleep each night.

  Sleep is vitally important to our health. It:

  • Improves our concentration
  • Makes us more alert
  • Increases our energy levels
  • Allows our body to recover and heal.
• Work/life Balance

  • An important lifestyle choice is to allow enough time for relaxation and play.
  • We all need to have fun and a laugh. This is often best done in the company of good friends.
  • We need to be aware of what makes us feel good and happy and to include this in our daily routine.
• Micro-organisms


  • small living things
  • most of them are too small to be seen with the naked eye
  • They can be seen only using microscopes
  • They are found in huge numbers almost everywhere
  • For example, they are present in the air, water and soil, on our skin, and inside plants, animals and humans
  • there are three types of micro-organism:

  1. Viruses
  2. Bacteria
  3. Fungi

  • Viruses and bacteria are too small to be seen by eye, but we can see some fungi
• Micro-organisms pt. 2

  • Most micro-organisms are of benefit.
  • They are important as they play crucial roles
• Benefits of Micro-organisms

  • Decomposition - which allows living things to be broken down and their minerals released so they can be recycled into new living things
  • Food production - they are involved in making many foods, alcohol, baking
  • Biotechnology - this is the use of living things, or parts of living things, to produce useful products such as drugs, flavourings, colourings, vitamins, artificial cloth and fuels
  • Water treatment
  • Digestive systems - bacteria in our intestines make vitamins, prevent the growth of disease - causing organisms and break down some foods.