Health and Disease Flashcards
What is the definition of a communicable disease?
is a disease which can be passed from one organism to another. It is an infectious disease. [e.g. Cold]
What does non-communicable mean?
Non-communicable – is a disease that cannot be passed between organisms. [e.g. cancer]
What are the three type of microbes?
bacteria, fungi and viruses
What are disease causing microorganisms called?
Pathogens
What microbe causes HIV?
Virus
What is the transmission method for HIV?
Exchange of body fluids during sex
Infected blood
What is a prevention method for HIV?
Using condoms
Avoid contact with people’s blood
Don’t share needles
What is the treatment for HIV?
No cure
Antiviral drugs can slow actions of virus.
What microbe causes tuberculosis?
Bacteria
What is the transmission method for tuberculosis?
airborne droplet infection
What is a prevention method for tuberculosis?
BCG vaccine
What is the treatment for tuberculosis?
Combination of antibiotics
What is the definition of ‘health’?
when a person is free from communicable and non communicable diseases
How is salmonella spread and treated?
Contaminated food
Antibiotics as it is caused by a bacteria
How is salmonella prevented?
Cook food thoroughly
How is Clamydia spread and treated?
Unprotected sex
Antibiotics as it is caused by a bacteria
How is HPV (Human Papilloma Virus) spread and what type of cancer can it cause?
Unprotected sex
Cervical cancer
How can HPV be prevented?
HPV vaccine given to teenagers
How is the fungal athlete’s foot prevented and treated?
Good hygiene measures
Anti fungal cream
How is potato blight (fungus) prevented?
Crop rotation
Name 3 bacteria diseases
TB, salmonella and Chlamydia
Name 3 viral diseases
HPV, Cold and HIV
Name 2 fungal diseases
Potato blight and Athlete’s foot
Why are aseptic techniques used in microbiology?
Aseptic techniques ensure the microbes being investigated don’t escape or become contaminated with another unwanted, and possibly pathogenic, microbe.
Name several aseptic techniques
-Not allowing the growth of microorganisms at body temperature (incubate at 25 degrees)
-Using flamed loops or sterile swabs when transferring cultures
-Flaming culture bottlenecks to prevent contamination
-Sterilising or disposing of all used equipment
-Washing hands thoroughly
What is an autoclave used for?
This is a type of pressure cooker that uses high pressure steam at 120oC to kill all organisms. It is used to sterilise agar dishes, culture media and other apparatus.
Name 3 first lines of defence
Blood clotting, skin and mucous membranes
Pathogens have special protein markers on their surface called…
Antigens
What do Lymphocytes produce?E
Antibodies are produced that are complementary in shape with a pathogen’s antigens
What is the role of a Phagocyte?
Phagocytes engulf and digest pathogens by using enzymes. The process is called Phagocytosis.
What is active immunity and give an example?
When the body produces its own antibodies.
Vaccinations or by getting the disease
What is passive immunity?
When you are given antibodies
E.g. anti venom vaccination or through the placenta or breastmilk
What structural defences do plants have?
plants have waxy cuticles and thick cell walls to prevent microorganisms entering
What chemical defences do plants have?
Plant produce antimicrobial chemicals which are harmful to microorganisms e.g mint or some can produce poisonous chemicals to stop insects feeding on them e.g. foxglove
What microbe does penicillin kill?
Bacteria
What was the first antibiotic and who discovered it?
Penicillin by Alexander Fleming
What did Florey and Chain do with penicillin?
Howard Florey and Ernst Chain carried out experiments to test penicillin on bacterial infections in mice in the 1930s
First of all, they developed a technique for purifying and concentrating penicillin from liquid cultures of Penicillium
Secondly, they showed that Penicillin was effective in preventing bacterial growth on agar plates
Florey and Chain used a fermenter in which they grew the fungus Penicillium to produce penicillin on a larger scale
What is down streaming?
A pure form of penicillin was made by a process known as downstreaming.
Downstreaming involves 3 steps → extraction, purification and packaging
What are the 3 stages drug development?
preclinical trials on cells/tissues, preclinical trials on animals and clinical trials on human volunteers
What happens during pre clinical trials on cells or tissues?
The drug is tested on cells in the lab on living cells and tissues.
Computer models may also be used.
Efficacy (does the drug work)and toxicity (does it have harmful side effects) are tested at this stage
What happens during pre clinical trials on animals?
The drug is tested on animals to see the effect in a whole organism
Efficacy, toxicity and dosage (the lowest dose that can be given & it still be effective) are tested at this stage
This stage can be used to test for side effects
As humans are different from animals there is no guarantee that the drug will work until it is tested on humans
What is peer review?
Peer review validates research by other scientists of equal standing who then provide feedback and suggest refinements
What happens during clinical trials on humans?
The drug is tested on human volunteers first, generally with a very low dose then increased. This is to make sure it is safe in a body that is working normally.
The next stage is to test on patients with the condition.
Once the drug is found to be safe then the lowest effective dose (optimum dosage) is tested at this stage (as too much of the drug may cause side effects and too little of the drug may be ineffective)
The drug can be licensed if the trials are successful
What are superbugs?
Superbugs are bacteria that are resistant to several antibiotics e.g. MRSA and C.difficile
How do we prevent the spread of superbugs in hospitals?
Increased hygiene, i.e. wear gloves, clean up bodily fluids immediately.
Isolate ‘superbug’ patients from other patients.
How do bacteria become resistant to antibiotics?
Bacterial resistance occurs due to a mutation in the bacterium’s DNA – a change to the genetic code, which means it is no longer affected by the antibiotic.
This mutated bacteria then reproduces to produce even more bacteria that carry this resistant gene
What is a vaccination made from?
Vaccination against a disease usually involves injecting a dead or modified
form of the disease-causing pathogen into the person’s blood.
How can smoking affect the body (include the words nicotine, tar and carbon monoxide)
Nicotine → is addictive and speeds up the heart rate
Tar → contains chemicals that can cause cancer (carcinogens)
Carbon monoxide → binds with the haemoglobin on red blood cells and stops oxygen from attaching. This means less oxygen is transported around the body.
How do vaccinations protect us from diseases?
The antigens on its surface causes the Lymphocytes to produce antibodies and memory lymphocytes to a level that will stop the person coming ill later.
What diseases can obesity cause?
Type 2 diabetes and CVD
What lifestyle factors contribute towards heart disease?
Diet high in fat
Smoking
Lack of exercise or obesity
Stress
High blood pressure
Drinking too much alcohol
How does a heart attack occur?
Buildup of cholesterol or fat in the coronary arteries (which forms a plaque)
This causes the coronary arteries to narrow and makes it more difficult for blood to flow through them
It may become so narrow that a blockage forms a clot
Blood carrying oxygen and glucose cannot get through to muscle tissue in the heart
The heart cannot respire or produced energy
The heart cells die and cannot contract (i.e. the heart stops beating) causing a heart attack
How does a stroke occur?
Cholesterol builds up in an artery in the brain
The artery becomes narrower as a blockage/clot forms
Blood flow is restricted
Part of the brain is starved of glucose and oxygen
Respiration is reduced or stopped.
Brain cells die.
A stroke can cause reduced brain function (e.g. paralysis)
Describe how an angioplasty procedure works
This a procedure used to widen the lumen of the coronary arteries
A catheter is inserted into the patient’s coronary artery which has a balloon at its end.
It also contains a tube of thin wire mesh called a stent.
When the balloon is inflated, it squashes the plaque and stretches the narrowed artery.
As the balloon is inflated the stent expands which holds the artery open.
Finally the catheter is removed, leaving the stent in place.
This increases blood flow as the lumen is now wider
What medication (tablets) are used to lower cholesterol levels?
Statins
What does aspirin do to the blood?
Aspirin thins the blood
This medication thins the blood by stopping fibrogen being converted into fibrin
This prevents blood clots occuring in the coronary arteries and reduces the chances of strokes or heart attacks by making the blood less ‘sticky’
What is the definition of cancer?
Uncontrolled cell division which can produce a tumour
What is skin cancer?
Uncontrolled cell division in the skin by UV rays
What is a benign tumour?
Benign tumours grow slowly, are often surrounded by a capsule and can usually be removed by surgery.
They are found in one place and for this reason are less life threatening.
What is a malignant tumour?
Malignant tumours are cancerous and can spread rapidly throughout the body as the tumour is not encapsulated
It can be life threatening and usually requires radiotherapy or chemotherapy. It is also more likely that it will return.
What is it important to screen people for different types of cancers?
The early detection of cancer can improve survival rates because the tumour may be smaller and may not have spread.
Screening programmes are in place to detect cancer as early as possible. These include: Screening for breast, cervical, testicular and skin cancer.
How does radiotherapy help treat cancer?
Radiation can kill living cells so beams of rays must be carefully directed at the cancerous tumour otherwise it can cause cancer in the healthy tissues surrounding it
How does chemotherapy help treat cancer?
This uses drugs to kill cancer cells.
Can have side effects such as normal cells being affected, nausea and hair loss.
How does immunotherapy help treat cancer?
This involves injecting specific antibodies into body that attach to the antigens on cancer cells
This ‘marks’ the cancer cell causing the phagocytes to recognise the cancer cells as foreign
The phagocytes will engulf and digest the cells by phagocytosis
This provides targeted treatment with few side effects
