Topic 5: Health, Disease and the Development of Medicine Flashcards
What is health?
A state of complete physical, mental and social well-being
What is disease?
A disorder of the body or mind that negatively affects an individuals health
What are the two types of disease?
Communicable and non-communicable
What is a communicable disease?
A disease that is passed directly between individuals and caused by a pathogen
What is a pathogen?
A disease-causing organism
What is a non-communicable disease?
A disease that cannot be transmitted between individuals, caused by lifestyle, environmental conditions and genetic mutations
What is a symptom?
A change experienced by an organism that indicates disease
Why does having an illness make an individual more likely to contract another disease?
A disease may weaken an individuals immune system making them increasingly susceptible to other infections
What is cholera?
Caused by bacteria, spread by drinking water or washing in water that had been contaminated with infectious faeces and the symptoms are diarrhoea and vomiting
How can the incidence of cholera be reduced?
Access to clean water and improved sanitation
What is tuberculosis?
Caused by bacteria, it’s an airborne bacteria spread by droplets infection and the symptoms are lung damage, chesty cough and wheezing
How can the transmission of TB be reduced?
Improved hygiene, infected individuals should avoid crowed area and increased ventilation in the individuals home
What is chalara ash dieback?
Caused by a fungus, spread via airborne and causes dark lesions on bark and blackened leaves which wilt and eventually die
How can the transmission of Chalara ash dieback disease be reduced?
Control the movement of ash trees, kill infected plants and replant with a different species
What is malaria?
Caused by protist, spread by mosquito vector and flu-like symptoms, damage to red blood cells and liver damage
How can the incidence of malaria be reduced?
Mosquito nets, insect repellent and cover arms and legs
What is stomach ulcers?
Caused by bacteria, transmitted orally by eating infected food or drinking infected water and symptoms are stomach pain, vomiting and nausea
How can the transmission of Helicobacter pylori be reduced?
Access to clean water, improved hygiene and improved sanitation
What is Ebola?
Caused by virus, spread by direct contact with infected bodily fluids and symptoms are fever, diarrhoea, vomit ting and internal bleeding
How can the transmission of Ebola be reduced?
Improved hygiene, isolating infected individuals and sterilisations of outbreaks areas
How can viruses cause disease?
They enter host cells and replicate inside of them, the host cells rupture, releasing new viruses
How do viruses differ from other microorganisms?
Viruses are not living organisms, they don’t reproduce and can only replicate inside a host cell
By what two pathways do viruses replicate inside living cells?
Lytic and Lysogenic pathway
What happen in lytic pathway?
Virus binds to specific receptors on host cell, virus injects it’s DNA into host cell and replicates it’s DNA using host cell machinery, new viral structures are produced and assembled then the host cell ruptures releasing new viruses
What happens in lysogenic pathway?
Virus binds to specific receptors on host cell, viral DNA injected into host cell and becomes integrated into host cell genome, viral DNA replicates each time the host cell divides, however, the cell remains normal and this triggers a cause the activation of viral DNA, it enters lytic pathway
What is HIV?
Caused by virus, spread by direct contact with infected body fluids and destroys white blood cells making the individual immunodeficient and increasingly susceptible to other diseases (leads to AIDS)
How can the spread of HIV be reduced?
Use of condom and protected sex, needle exchange, screening blood for HIV and deterring infected mothers from breastfeeding
What is chlamydia?
Cause by bacteria, spread through sexual/direct contact with infected genital fluids and can result in infertility
How can the transmission of Chlamydia be reduced?
condoms, protective sex and screening
What are some examples of non-communicable diseases?
Cancer, diabetes, cardiovascular diseases and chronic respiratory diseases
What is a risk factor?
A variable associated with a greater chance of developing a disease or infection
What factors that can affect the risk of developing a non-communicable disease?
Lifestyle, environmental factors and genetics
what does ‘correlation doesn’t mean causation’ mean?
Correlation between a risk factor and a disease doesn’t mean that the risk factor causes the disease, other factors may be involved and some may be linked
How does exercise affect the risk of some non-communicable diseases?
Regular exercise decreases fat stored reducing obesity and it decreases heart rate recovery time and blood pressure lowering the risk of CVD
How can diet affect the risk of some non-communicable disease?
Diet high in saturated fat raises blood cholesterol levels, increasing the deposition of fatty deposits in the arteries so greater risk of CVD, obesity and the consumption of large armoury’s of simple-sugars increases the risk of type 2 diabetes and malnourishment increases the risk of deficiency diseases
What is the body mass index?
A value based on height and mass used to categorise an individual as underweight, normal weight, overweight or obses
How is BMI calculated?
Mass / (height)2
Why isn’t BMI always an accurate measure of obesity?
Fate and muscle tissue cannot be distinguished so athletes may be incorrectly categorised as obese
How is an individual waist-to-hip ratio calculated?
Waist circumference / hip circumference
How does alcohol affect the risk of some non-communicable diseases?
Alcohol broken down into toxic products in the liver which build-up and cause cirrhosis, alcohol raises blood pressure this increasing the risk of CVD and toxic products in alcohols can cause mutations to DNA, increasing the risk of cancer
How does smoking affect the risk of some non-communicable diseases?
Raises heart rate, increasing the risk of CVD, lowered the ability of red blood cells to carry oxygen so heart rate increases causing higher risk of CVD and smoking increases the risk of lung diseases