B6.3-part 1 Monitoring and maintaining health Flashcards
Describe the relationship between health and disease
- if a person is in good health, they don’t have any type of disease
- a disease is a condition caused by any body part not functioning properly
- diseases can affect both mental and physical health
State the definition, causes and examples of communicable diseases
- diseases that can be spread between organisms
- also called contagious or infectious
- most caused by microorganisms
- most microorganisms cause no harm, but pathogens (microorganisms) cause disease when they enter the organism - these are parasites
Type of pathogen - example of animal disease - example of plant disease
Fungi - athlete’s foot - powdery mildew
Bacteria - tuberculosis - crown gall disease
Viruses - influenza (flu) - tobacco mosaic disease
Protozoa - malaria - coffee phloem necrosis
State the definition, causes and examples of non-communicable diseases
- cannot be spread between organisms
Causes:
- a poor diet - vegetable + fruitless diet can result in vitamin and mineral deficiencies
- obesity - can lead to arthritis, type 2 diabetes, heart disease and stroke
- inheriting a genetic condition - e.g. cystic fibrosis
- body processes not operating correctly - uncontrollable cell division may lead to cancer
Describe the interactions between different types of disease (HIV and TB; HPV and cervical cancer)
Although most communicable and non-communicable diseases have separate causes, some conditions are linked.
HPV and cervical cancer
- Human papilloma virus causes most forms of cervical cancer
- periphery usually recover from an HPV infection without long term problems
- in some cases, HPV causes cell changes that lead to cervical cancer
- Girls in the UK are now routinely vaccinated against this virus, which has significantly reduced the no. of cases of cervical cancer
HIV and TB
- human immunodeficiency virus, which causes AIDS (acquired immune deficiency syndrome), weakens a person’s immune system, making it much easier for other microorganisms, like the tuberculosis-causing bacteria, to cause disease
- many people with HIV die from tuberculosis
Describe how communicable diseases can be spread between animals
Pathogens enter an animal’s body in order to cause harm:
- through cuts in skin - from injury, or insect/animal bites
- through digestive system - foods and drinks shared
- through respiratory system - by inhaling pathogens
- through reproductive system - during sexual intercourse
The closer together organisms live, the greater risk of a disease being passed on
Describe how communicable diseases can be spread between plants
- through soil and water in which the plants grow
- vectors, such as insects
- direct contact of sap from an infected plant with a healthy plant. Sap can be released by agricultural damage, or through animals feeding on plants
- the wind. Fungal spores can be blown between plants. Infected seeds can also be blown across large distances, resulting in the spread of a disease
Explain how pathogens cause disease
- incubation period - time delay between harmful organisms entering body and you feeling unwell
- during this period, pathogens reproduce rapidly
- as they grow + reproduce they cause cell damage
- some also produce toxic waste products - these toxins cause a range of symptoms like fevers, rashes and sores
- Viruses can not replicate by themselves - they can only reproduce by ‘taking over’ and using a host organism’s cell to make more viruses
State the steps of viral replication
- virus attacks a cell
- inserts it’s genes
- ‘tells’ the nucleus to copy its genes
- new viruses are made
- cell bursts, releasing the new viruses and destroying your cell
Explain how scientists monitor disease
- for disease outbreaks they normally study the incidence of a disease - rate at which new cases occur in a population over a period of time
- for non-communicable diseases, studies often last for long periods and involve many people
- a typical study may look at the no. of cases per 10000 people, per year, over a 10-year period
- outcomes from studies like these provide scientists with evidence for the effectiveness of disease treatments or prevention techniques
Explain how the spread of communicable diseases between humans (animals) can be reduced or prevented
- covering your mouth + nose when coughing/sneezing - use a tissue and immediately discard it
- not touching infected people or objects - e.g. chicken pox and mumps
- using protection - e.g. condoms to help prevent STIs being transferred (body fluids prevents from being exchanged during sex)
- not sharing needles - needles used to inject drugs should be disposed of immediately after single use - e.g. HIV and hepatitis can be passed on in blood on the needle
Being hygienic:
- washing your hands - before eating
- cooking food properly - some animals contain bacteria (E.coli, salmonella) which could cause food poisoning - thorough cooking kills bacteria
- drinking clean water - untreated water contain microorganism that cause diseases like cholera and typhoid. Boil water / use sterilisation tablets
- protect yourself from animal bites - use insect-repellent sprays
Explain how the spread of communicable diseases between animals and plants can be reduced or prevented
First, diseases are identified by changes to an organism’s appearance, or through identifying the pathogen by its DNA or antigens (proteins on surface of microorganism). Once identified:
- diseased plant material is normally burnt to prevent disease spreading
- animals may be treated using drugs although some communicable diseases require whole herds to be slaughtered
- livestock cannot be moved
- chemical dips are installed on farms to kill pathogens on footwear
- farmers also spray plants with fungicides to prevent fungal disease
- get their animals vaccinated against some pathogens
Describe common fungal infections (athlete’s foot)
Athlete’s food
- caused by a group of parasitic fungi called dermatophytes
- feet provide a warm, humid environment, ideal for dermatophytes to live and multiply in
- symptoms (effects of disease) are cracked, flaking itchy skin
- normally treated using an anti-fungal cream
- very contagious - spread through direct and indirect contact
Describe common bacterial diseases (food poisoning)
Food poisoning
- caused by growth of microorganisms in food
- most serious types are caused by bacteria and the toxins they produce
3 main groups:
- Campylobacter - found in raw meat, unpasteurised milk and untreated water
- Salmonella - raw meat, eggs, raw unwashed vegetables and unpasteurised milk
- E.coli - only some types cause food poisoning - found in raw and undercooked meats, and unpasteurised milk and dairy products
- all these bacteria can survive refrigeration and freezer storage, but thorough cooking kills them
- common symptoms - stomach pains, diarrhoea, vomiting and fever
- most get better within a few days
- in some cases, doctors may need to use a drip to replace fluids
- in rare cases it can kill
Describe some examples of sexually transmitted diseases
STIs are passed on between people through unprotected sex or genital contact - passed on through bodily fluids or by skin on skin contact
- people use condoms to protect themselves
- many diseases initially don’t have symptoms so makes their spread more likely as people are unaware that they are infected
Infection - cause - symptoms - treatment
Chlamydia - bacteria - pain when urinating, discharge from penis/vagina - antibiotics
Gonorrhoea - bacteria - burning pain when urinating, vaginal discharge - antibiotics
Genital herpes - virus - painful blisters or sores - no cure
HIV - virus - weakened immune system, often resulting in AIDS - no cure, symptoms controlled with antiretroviral drugs. Lifetime treatment required
Explain the difference between HIV and AIDS
- HIV invaded WBC and reproduces inside cells
- this weakens your immune system as affected cells show be producing antibodies to defend against disease but cannot
- without them, body becomes target of everyday infections and cell changes that cause cancer
- AIDS is final stage of HIV infection, when body can no longer fight life-threatening infections like cancer