Staying healthy
Nutrition and healthy habits, BMI, bones and joints, infection control, inherited conditions and medical technology.
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Before you begin
What keeps the body healthy, and how medicine helps when it is not. This topic covers diet and habits, bones and joints, BMI, inherited conditions, infections and their treatment, and how dialysis and transplants support failed kidneys.
Be comfortable with: dividing and squaring numbers, and the idea that microbes can cause disease.
Learning goals
- Active lifestyle
- Balanced diet
- Sufficient rest
- Good hygiene
- Meaning of balanced diet
- Roles of nutrients
- Calculating and interpreting BMI
- Undereating and over-exercising
- Fracture and osteoporosis
- Cartilage and ligament
- Arthritis, dislocation and sprain
- Reducing bone and joint risk
- Bacterial and viral diseases
- Antimicrobial agents
- Completing antibiotics
- Vaccination
- Hereditary conditions
- Limits of organ-support technology
Syllabus statements covered
- state the following ways in maintaining good physical health: — adopting an active lifestyle
- state the following ways in maintaining good physical health: — eating a balanced diet
- state the following ways in maintaining good physical health: — having sufficient rest
- state the following ways in maintaining good physical health: — practising good hygiene
- show an understanding of what is meant by a balanced diet
- state the dietary importance of carbohydrates, dietary fibre, fats, proteins, minerals (calcium), vitamins (vitamin D) and water
- recall and determine the body mass index, BMI = mass (kg)/[height (m) × height (m)] to deduce whether an individual's mass is in the healthy range
- describe the health risks of undereating and over-exercising to lose weight
- describe the following problems related to bones: fracture and osteoporosis
- state the following parts associated with common joints and their functions: cartilage and ligament
- describe the following problems related to parts associated with joints: arthritis, dislocation and sprain
- state how diet and level of physical activity can affect the risk of developing problems related to bones and joints
- state that diseases can be caused by bacteria or viruses (structures of bacteria and viruses are not required)
- describe the effects of antimicrobial agents (e.g. antiseptics, disinfectants) on the population growth of microbes (e.g. bacteria, fungi)
- explain the importance of completing a prescribed course of antibiotics for diseases caused by bacteria
- state that diseases caused by bacteria and viruses may be prevented by vaccinations
- state that some diseases/conditions are hereditary by nature (e.g. sickle cell disease, thalassemia, colour deficiency)
- state some limitations of the use of technology in replacing or supporting malfunctioning organs (e.g. tissue rejection after organ transplant, lifelong dependence on kidney dialysis)
Lessons
Work through them in order.
- Healthy habits and nutritionExplain how activity, rest, hygiene and each nutrient in a balanced diet support the body.
- BMI and weight decisionsCalculate BMI, compare it with a supplied appropriate reference, and explain the limits of the health conclusion.
- Bones and jointsMatch cartilage and ligaments to their roles, and identify fractures, sprains, dislocations and arthritis.
- Infection prevention and treatmentDistinguish vaccination, antibiotics, antiseptics and disinfectants, and explain resistant bacterial survival and prescribed medicine use.
- Inherited conditionsDistinguish sickle cell disease, thalassaemia and inherited colour vision deficiency from infections, without treating inheritance as contagion or certainty.
- Kidney dialysis and transplantationExplain repeated dialysis support and compare it with a donor kidney, including the need for ongoing care and the risk of tissue rejection.
Practise and check
Or choose
Topic reference
Quick reference
| Treatment | What it does | What it does not do |
|---|---|---|
| antibiotic | kills or stops the growth of bacteria | work against viruses |
| vaccine | prepares the body to fight a disease in future | cure an illness someone already has |
| antiseptic | reduces microbes on skin | belong on surfaces |
| disinfectant | reduces microbes on surfaces | belong on skin |
| dialysis | removes wastes and excess water from the blood | cure kidney failure; it must be repeated |
| transplant | replaces a failed kidney with a donor one | avoid the risk of rejection |
BMI = mass in kg ÷ (height in m)²
Core knowledge to remember
- A balanced diet gives the right amounts of energy, nutrients, fibre and water; no single nutrient can replace it.
- Cartilage covers bone ends; ligaments join bone to bone.
- Inherited conditions, such as sickle cell disease, thalassaemia and colour vision deficiency, are passed on through genes, not caught.
- Antibiotic resistance spreads when resistant bacteria survive and multiply.
- BMI is a screening measure, not a diagnosis.
Common mistakes
- Thinking antibiotics work against viruses.
- Saying a vaccine cures an existing illness.
- Thinking an inherited condition can be caught.
- Using adult BMI ranges for a child.