What is health
A state of complete physical, mental and social wellbeing
What is meant by the term communicable diseases?
Diseases that can be passed from organism to organism
What is meant by the term non-communicable disease
Diseases that are not passed from organism to organism
What is a pathogen
A microorganism that causes diseases
What are the four pathogens
Bacterium, virus, protist, fungi
How does a bacterium pathogen make you feel ill
It releases toxins that makes us feel ill and some types of bacteria invade and destroy body cells
How does a virus pathogen make you feel ill
Viruses take over the body cells DNA causing the cell to make toxins or causing damage when new viruses are released from cells
What type of pathogen is cholera
Bacterium
What are the symptoms of cholera
Watery pale coloured diarrhoea often in large amounts
What type of pathogen is malaria
Protist
What are the symptoms of malaria
Fever, weakness and chills, sweating
What type of pathogen is HIV
Virus
What are the symptoms of HIV
Flu-like symptoms, often no symptoms for a long time
What type of pathogen is tuberculosis
Bacterium
What are the symptoms of tuberculosis
Lung damage seen in blood speckled mucus, weight loss, fever and chills, night sweats
What type of pathogen is chalara ash die back
Fungus
What are the symptoms of chalara ash die back
Leaf loss, bark lesions, dieback of the top of the tree
How is cholera spread
Water
How can cholera be prevented
Boil water to kill bacteria before drinking, wash hands thoroughly after using the toilet to prevent spread by touch
How is tuberculosis spread
Airborne
How to prevent the spread of tuberculosis
Ventilate buildings to reduce the chance of breathing in bacteria in droplets of mucus coughed out by an infected person, diagnose infected people promptly and give antibiotics to kill TB, isolate infected people
How is malaria spread
Mosquito as a vector
How to prevent the spread of malaria
Killing mosquitoes and using nets
How is chalara ash die back spread
Airborne
How to prevent the spread of chalara ash die back
Remove infected trees
How is chlamydia and HIV spread
Contact with sexual fluid or mother to foetus
What type of pathogen is chlamydia
Bacterial
How are STIs prevented
Condoms, screening blood and people, sterile needles (HIV), antibiotics(chlamydia)
What are examples of physical barriers
Mucus, cilia and skin
What are examples of chemical defences
Lysozyme and hydrochloric acid
How is mucus a barrier
It is sticky in the breathing passages and lungs and traps pathogens
How is cilia a barrier
It moves the mucus that traps pathogens away from the lungs
How is skin a barrier
It is too thick for pathogens to get through
How is lysozyme a defence
Its enzyme in tears kills bacteria by digesting its cell walls
How is hydrochloric acid a defence
It kills pathogens in food and drinks
Step 1 of the immune system
Each pathogen has a unique antigen on its surface
Step 2 of the immune system
A lymphocyte releases an antibody that fits the antigen and is activated
Step 3 of the immune system
The lymphocyte divides many times to produce clones of identical lymphocytes
Step 4 of the immune system
Some of the lymphocytes produce lots of antibodies that stick to the pathogen and destroy it, others stay in the blood as memory lymphocytes ready to respond if the same antigen returns
What is an antigen
A protein on the surface of a pathogen
What is an antibody
A protein produced by lymphocytes that attaches to a specific antigen on a microorganism and helps destroy or neutralise it
What is a lymphocyte
A white blood cell that produces antibodies to kill antigens
What is a memory lymphocytes
They can recognise an antigen introduced into the body from a prior vaccination or infection
How do vaccines work step 1
Dead or weakened antigens from the pathogen are inserted
How do vaccines work step 2
The persons lymphocytes produce antibodies against the pathogen and memory lymphocytes to respond if the pathogen returns
How do vaccines work step 3
If the real antigen returns the memory lymphocytes will give a rapid secondary response
How do antibiotics work
They kill bacteria inside the body
Why do antibiotics only kill bacterial diseases
They inhibit cell processes in the bacterium but not host organism
New medicines development and testing stage 1
Discovery
New medicines development and testings stage 2
Pre clinical testing in the lab. Drugs are tested in the lab to make sure it gets into the cells without harming them and damages pathogens inside cells
New medicine development and testing stage 3
Clinical testing step 1. A healthy volunteer is given a small dose to ensure it isn’t harmful
New medicines development and testing stage 4
Clinical testing step 2. People with the disease are given the drug to test efficacy and optimum dose
Factors that affect the risk of developing non communicable diseases
Genes, age, sex, lifestyle, environmental factors
How does alcohol cause liver disease
Ethanol is poisonous and is in alcohol. When it is absorbed from the gut and goes down to the liver to be broken down the liver is directly in contact with the toxins in ethanol
How does smoking cause cardiovascular disease
Substances in cigarettes can narrow blood vessels
Equation for BMI
Kg/metres2
Wait:hip ratio
Someone with a high waist hip ratio is more at risk of non communicable diseases
What lifestyle changes can tame cardiovascular disease
Stop smoking, loose weight, exercise
Pros of lifestyle changes
No side effects, can reduce the chance of other conditions, cheap
Cons of lifestyle changes
May take time and not actually work
How can medication tame cardiovascular disease
Reduces blood pressure
Pros of medication
Starts working immediately, easy, cheap
Cons of medication
Needs to be taken long term, side effects, clashes with other medication
How can surgery tame cardiovascular disease
A new blood vessel is inserted to bypass blocked coronary arteries
Pros of surgery
Long term solution
Cons of surgery
Risk of recovery, expensive, difficult, can develop an infection afterwards
