Disease Flashcards
What is health?
A state of physical and mental well being
What is a disease?
Anything that negatively affects health
What can ill physical health lead to?
Depression and other mental illnesses
What are the two types of diseases?
- Communicable diseases
- Non-communicable diseases
What factors of non-communicable disease affect health?
- Diet
- Stress
- Life situations
What are risk factors?
Factors which increase the risk of a particular disease
What are the two general types of risk factors?
- Aspects of your lifestyle
- Substances in the body or environment
What is the key fact to remember about non-communicable diseases about cause and correlarion?
A correlation does not mean or prove causation
What is CVD and it’s main causal links?
Cardiovascualr Disease (disease of the whole circulatory and respiratory systems) Caused by diet, lack of exercise and smoking
What part of the body does coronary heart disease refer to?
The heart and blood vessels
What is the role of the coronary arteries?
To provide the heart muscle with oxygen and glucose for anaerobic respiration
What can block (coronary) arteries?
Fatty deposits
What are fatty deposits and what are their effects?
Fatty deposits are a combination of cholesterol and other fats building up in the vessels, restricting the availabilty of oxygen getting to a particular muscle
What is coronary artery fatty blockage generally associated with? What does it lead to?
High blood pressure and poor diet which leads to atherosclerosis
What are the typical effects of athersclerosis?
Patients suffer tiredness, shortage of breath, and chest pain associated with a loss of flexibility in the arteries
Why are arteries required to be felxible?
Because of the heart beats and consequent pulsations
What are the possible treatments for atherosclerosis?
- Statins
- Stents
- Bypass Surgery
How do statins work?
they reduce cholesterol levels which reduces the rate of fatty deposits in the coronary arteries
What are stents?
Tubes inserted into arteries to hold them open
What is bypass surgery?
When (typically) a vein is removed from the leg anf used to make a bypass around the artery blockage
Other than atherosclerosis, what is another issue with the heart and how is it solved?
- The heart could have faulty valves which may allow blood to flow backwards in the heart.
- The valves can be transplanted with biological or mechanical ones
- Sometimes the whole heart can be transplanted
What are the risk factors for type 2 diabetes?
Obesity and a lack of exercise
What is the effect of alcohol on type 2 diabetes?
Body cells do not respond to the hormone insulin, which helps control the glucose level in the blood
What is the risk factor of liver misfunction?
Alcohol
What are the effects of alcohol on liver misfunction?
Long-term alcohol usage can cause liver cirrhosis. The cells in the liver stop working and are replaced by scar tissue. This stops the liver from removing toxins, storing glucose as glycogen and making bile
What is the risk factor of brain malfunction?
Alcohol
What are the effects of alcohol on brain malfunction?
Excessive alcohol can alter the chemicals in the brain, which pass messages between nerve cells. This can cause anxiety and depression and reduced brain functions
What is the risk factor of lung disease and cancer?
Smoking
What are the effects of smoking on lung disease and cancer?
Smoking can cause cancer in many parts of the body. It also increases the chances of having asthma, bronchitis and emphysema.
What are the risk factors of underdevelopment in unborn babies?
Smoking and Alcohol
What are the effects of smoking and alcohol on underdevelopment in unborn babies?
Alcohol and cigarette chemicals in the mother’s blood pass through the placenta to the baby. Without a fully developed liver, the baby cannot detoxify these as well as the mother can. This can lead to miscarriage, premature birth, low birth weight and reduced brain function
Whar are the risk factors for cancer?
Carcinogens and ionising radiation
What are the effects of carcinogens and ionising radiation on the body?
These are chemicals and radiation that cause cancer. Tar in cigarettes, asbestos, UV light and X-Rays are all examples. These damage the DNA in the cells and cause them to multiply uncontrollably.
What is cancer formed as a result of?
Tumours
How are tumours formed?
Due to uncontrollable division of body cells
What is a benign tumour?
A tumour which is contained within a membrane. It is usually small and unable to spread.
What is a malignant tumour (cancer)?
A tumour which spreads into other tissues
How do malignant tumours spread through the body to form secondary tumours?
Through the bloodstream
What are the possible ways in which cancer can be tried to be combatted?
Through chemotherapy or radiotherapy which target at trying to kill the tumour cells
What sort of things can increase the risk of cancers?
- Lifestyle choices (smoking, excess alcohol etc.)
- Exposure to radiation (UV light)
- Pathogens (HPV which causes cervical cancer)
What is the pathogen type of measles?
Virus
What is the pathogen type of HIV?
Virus
What is the pathogen type of salmonella?
Bacteria
What is the pathogen type of gonorrhoea?
Bacteria
What is the pathogen type of malaria?
Protist
What is the pathogen type of the tobacco mosaic virus?
virus
What is the pathogen type of rose black spot?
Fungus
How is measles transmitted?
Inhalation of droplets from coughs and sneezes
What are the symptoms of measles?
Fever and a red skin rash. Can be fatal with complications.
How can measles be prevented?
Through vaccination
How is HIV transmitted?
Blood borne, spread through mixing of body fluids and sexual contact
What are the symptoms of HIV?
It is like a flu in the early stage but AIDS develops when the immune system is so badly damaged that it can no longer deal with other infections
How can HIV be prevented?
Through condoms and sterile needles
How is salmonella transmitted?
Ingested with food
What are the symptoms of salmonella?
Fever and abdominal cramps, vomiting and diarrhoea caused by both the bacteria and the toxins they produce
How can salmonella be prevented?
Maintain hygiene in food preparation areas
Vaccinate poultry
How is gonorrhoea transmitted?
Sexual contact
What are the symptoms of gonorrhoea?
Pain when urinating
Thick yellow or green discharge from the penis or vagina
How can gonorrhoea be prevented?
Use of a condom
Treated with antibiotics to control the spread
How is malaria transmitted?
Mosquito vector
What are the symptoms of malaria?
Recurrent episodes of fever and can be fatal in many cases
How can malaria be prevented?
Use of mosquito nets and prevention of mosquitos from breeding
How is the tobacco mosaic virus transmitted?
It is air borne
What are the symptoms of tobacco mosaic virus?
A distinctive mosaic pattern of discolouration on the leaves which causes stunted growth due to lack of photosynthesis
How can the tobacco mosaic virus be prevented?
The separation and removal of infected plants (commonly tomatoes from greenhouses)
How is rose black spot transmitted?
Through water and the wind
What are the symptoms of rose black spot?
Purple and black spots form on the leaves which then fall from the plant. This reduces photosynthesis and therefore growth
How can rose black spot be prevented?
Through the use of fungicides and removal of infected leaves
What does our body have which stops pathogens gettung into us?
Primary defences
How is our nose a primary defence?
The hairs in the nose act as a basic filter to trap and remove pathogens before they can infect us
How is our skin a primary defence?
- It is a microbe proof barrier to protect most of the body
- Scabs form on the skin to prevent pathogens getting in and excess blood loss
How is our stomach acid a primary defence?
It is intended to kill pathogens in our food
How do cilia and mucus act as a primary defence>
There is a lining of cilia and mucus in the bronchi and trachea. The mucus traps the pathogens and the cilia move it up and out the lungs
What is a pathogen?
An organism/microorganism that causes disease
What is our bodies second line of defence (when pathogens get into our bodies)?
Phagocytosis
What type of defence is phagocytosis?
Non-specific
What does a non-specific defence do?
Targets anything foreign in the body (like pathogens)
What happens during phagocytosis, in general?
A phagocyte cell absorbs and digests a foreign organism (including pathogens)
Describe the three main steps of phagocytosis:
- Bacteria is engulfed by the phagocyte
- The bacteria is digested by enzymes in the phagocyte
- The phagocyte ‘displays’ the antigens of the pathogen to stimulate the specific immune response
What is the third line of defence called?
The specific immune response
What type of cells does the specific immune response involve? What is special about them?
Lymphocytes- they recognise only 1 specific complementary antigen
What do lymphocytes produce?
Antibodies or antitoxins
What are antibodies? What do they do?
Small proteins that are complementary to antigens. They bind to pathogens, causing them to stick to each other or preventing them from replicating
What are antitoxins? What do they do?
They are small proteins that render toxins (poisons) harmless
What are memory cells? What do they allow us to do?
They are lymphocytes which remain in our blood stream after making us better. This means that if we get infected again, these cells produce a higher and faster response before we get ill. We become immune.
What does immunity from memory cells mean?
That a further exposure to the same pathogen causes faster, bigger and longer response so we don’t get ill
What does a vaccine try to mimic?
The first exposure to a pathogen so we get memory cells and therfore when we are next exposed to a pathogen, we are immune.
What is a vaccine?
A dead or weakened pathogen (or the antigens of it) that is usually injected into the body to raise the immune response.
What type of immunity is a vaccine?
Active Immunity
What is herd immunity?
When enough individuals in a community are vaccinated so outbreaks are prevented and provides some protection for unvaccinated individuals.
How is diet a factor in obesity?
Eating too much food and the wrong food causes it to be stored as excess fat
What is a factor and explanation of diarrhoea-linked diseases?
Poor water quality as the untreated water has pathogens in
What is a factor and explanation of HIV and AIDS?
Drug use as virus can be passed from person to person by the sharing of needles
What does a bacteria do to your body?
It can damage cells or produce toxins which make you ill
What do viruses do to your body?
They live and reproduce inside cells, causing cell damage
What are the main differences between a virus and bacteria?
- A virus is much smaller
- Viruses reproduce within cells
- Viruses are non-living
- Viruses are always pathogens
Why does a body’s temperature rise when a bacteria is inside it?
It is a response to the damage in the body or toxins. The increase in temperature slows down the growth of the bacteria.
How is the common cold spreas?
Through the air or water droplets
What is a communicable disease?
A disease which is caused by pathogens. It can be spread.
What do antibiotics do?
Antibiotics cure bacterial diseases by killing bacterial pathogens. Specific antibiotics must be used to treat specific pathogens.
Why aren’t antibiotics uses to kill viral pathogens?
Antibiotics don’t affect viral pathogens as viruses are found inside host cells, and you cannot take a drug which destroys lots of your own cells
What is antibiotic resistance driven by?
- Overuse of antibiotics
- And the lack of completion of a course of antibiotics
What type of drug can be used to treat HIV and other viruses?
Anti-virals
What cells are attacked by HIV?
White Blood cells
What are the common foods which contain salmonella?
Unpasteurised milk, raw eggs and poultry (e.g. chicken and turkey)
Explain the stages of infection with bacterial pathogens:
- Pathogen enters the body (gets through primary defences)
- Replicates rapidly in the body
- Produces toxins
- Syptoms caused by the accumulation of toxins
In which organ does the malaria parasite tend to multiply in?
Liver
What are the two ways in which malaria can be controlled?
- Prevent breeding (chemicals, pesticides, infertile males)
- Prevent biting (repellents, nets)
What are the two ways in which the skin defends against pathogen attack?
- Physical barrier
- Antimicrobial - produces antimicrobial secretions which destroy pathogens
How do platelets prevent pathogen entrance through a wound?
- Wound is formed and the platelets are exposed to the air
- Form mesh and trap blood cells
- Forms clot/scab
- Prevents pathogen entrance into the body
How are medical drugs usually made?
They are usually naturally occuring or made similar to natural chemicals
What type of drug is Aspirin? Where does it come from?
Painkiller that comes from the bark of a willow tree
What are the limitations of a painkiller?
It can treat the symptoms of a disease but cannot kill the pathogens
What medicine is used for heart medication and where does it come from?
Digitalis from foxgloves
What type of drug is Penicillin?
Antibiotics
What was Penicillum discovered from and who discovered it?
Discovered by Alexander Fleming, made by the mould Penicillium notatum.
What three main things are drugs tested for before they can be prescribed by doctors?
- Toxicity (side effects)
- Efficacy (does it actually work?)
- Dose (quantity and how often)
What is the first stage of drug testing/trialling?
Testing the drug on cell lines
How can ‘immortal cells’ grow very quickly?
Using the method of tissue culture
What is the second stage of drug testing/trialling?
Testing on laboratory animals . All drugs need to be tested in this way to carry a licence
What is the third stage of drug testing/trialling?
Testing on humans
What are the two sub-stages of the clinical testing?
- Testing Healthy Volunteers
- Testing Patients
How are the drugs tested with patients in the third stage of testing?
Double blind
What is a double blind test?
Where neither the doctor nor the patient knows if they are taking the drug or placebo
Why are tests done double blind?
To remove bias
What is a placebo?
A placebo looks, tastes and smells like the drug, but has no drug present (or is the best available drug at the time). It is used as a control in drug trialling
How do you make monoclonal antibodies?
- Mouse is injected with antigen from particular pathogen
- B lymphocytes that produce antibodies against the antigen are taken from the mouse
- they are fused with tumour cells to create hybridoma cells
- the hybridoma cells are cloned and reproduce rapidly to produce lots of identical cells which all produce monoclonal antibodies against the pathogen
- these antibodies are then collected and purified
What shows if a pregnancy test is positive or negative ?
Negative = single band positive = double band
What is specific to the two monoclonal antibododies in a pregnancy test?
- First one is specficto HCg (pregnancy)hormone
- Second is specific to first monoclonal antibody
What has to be made in a magic bullet therapy?
A monoclonal antibody is made that is specific to an antigen found as an infected or tumour cell
What is attached to the monoclonal antibody in magic bullet therapy?
A drug that will treat the targeted disease
What can magic bullet therapies allow us to do?
Allows us to target powerful drugs to only infected or tumour cells, reducing side effects
Describe the four step process that monoclonal antibodies can be used to test for chemicals or antigens:
1) Wells in a plate are coated with the antigen of interest
2) A blood sample from a patient is added
3) After washing, a monoclonal antibody specific to human antibodies and attached to an enzyme is added
4) After washing again, a substrate is added which is specific for the enzyme on the Mab (typically pink). This turns yellow when mixed with an enzyme.
What are the zones called on agar plates where an antibiotic has created a clear area?
Zones of inhibition
What do aphids do?
They are insects which suck the sap from the phloem inside the stem of a plant.
What is the result of aphids?
Growth is reduced, making leaves wilt and discolour
How can aphids be stopped?
By encouraging ladybirds as they prey on them
What does nitrate deficiency in plants result in?
A lack of ability to make proteins from amino acids which means plants suffer stunted growth
What does a magnesium deficiency in plants result in?
A lack of chlorophyll, since it is made from magnesium, so the leaves turn from green to yellow. This is called chlorosis.
What are common indicators of plant disease?
- Stunted growth
- Spots on leaves
- Areas of decay
- Growths
- Malformed stems or leaves
- Discolouration
- The prescence of pests
What physical defence adaptations do plants have to resist invasion of microorganisms?
- Cellulose cell walls
- A tough waxy cuticle on the leaf
- Layers of dead cells around stems (bark) which fall off
What chemical defence adaptations do plants have?
- Antibacterial chemicals (e.g. mint, witch hazel)
- Poisons to deter herbivores (e.g. nettles)
What mechanical defence adaptations do plants have?
- Thorns and hairs to deter animals
- Leaves which droop or curl when touched
- Mimicry to trick animals
What are the effects of short term alcohol usage?
Slows down reactions (affects nervous system)
Unconsciousness
Why is ionising radiation a risk factor for cancer ?
The ionisiing radiation penetrates cells, damages their DNA and causes mutations
What process needs to be carried out before a claim can be believed?
Data from scientific research needs to back up claim. A group of independent researchers gather results which are then reviewed before being published in a scientific journal.
What does regular exercise do?
Lowers blood cholesterol and reduces the fatty deposits in the coronary arteries, lowering the risk of heart disease. Lowers the risk of high blood pressure abd type 2 diabetes.
Why do people gain weight as they get older?
Their metabolic rate slows so their body doesn’t use as much energy from food. The excess food not used for energy is stored as fat. A person may also not do as much physical activity as they get older so the fat’s energy might not be transferred so much
Why do people who regularly exercise stay a healthy weight?
Exercise increases muscle tissue which increases metabolic rate. Therefore, more energy from food is used and not stored as fat ( stay healthy weight)
What can smoking cause?
Coronary heart disease, lung cancer, bronchitis, COPD, premature birth, low birth weight and stillbirth
Why can smoking cause issues to do with babies and fetus?
The mother’s body who smokes carries carbon monoxide in her blood which restricts the amount of oxygen the fetus gets
Which substance in tobacco smoke causes the breakdown of alveoli?
The carcinogen tar
Which substance in tobacco smoke causes an increase in blood pressure?
Nicotine
Which substance in tobacco smoke causes throat cancer?
Tar
How can radiotheraphy or chemotherapy be used to treat cancer?
Radiation or chemicals are used to stop cancer cells dividing
What are the differences between tumour cells and normal cells?
- Tumour cells divide uncontrollably
- Tumour cells divide faster
- Tumour cells live longer
Compare the dangers to health of benign and malignant tumours:
Both are caused by the uncontrollable division of cells and can be life threatening. They interfere with the function of a issue after all. However, malignant tumours can spread around the body and cause secondary tumours. This mkaes them more difficult to treat and control. Benign tumours are contained which makes them easier to be treated and no longer affect organ once removed
Why can monoclonal antibodies prevent the harming of other bodily cells without disease?
They bind to diseased or damaged cells only so the drug on the antibodies only affects those cells
How can monoclonal antibodies be used to treat cancer?
- trigger immune response to kill cancer cells
- block receptors on surface of cancer cells so stop growth stimulating molecule attaching to it.
- carry drugs that stop cells growing or dividing
Why aren’t monoclonal antibodies more widely used?
creating the antibodies and attaching to drugs is harder than expected. They are also made from mouse antibodies which trigger an immune response in humans
What happens after the many hybridoma cells have been made?
They are collected and purified
Why are drugs tested on living animals?
To check the drug isn’t harmful to living organisms and works in whole organisms
Why are drugs tested on healthy volunteers?
To check the side effects of the drug
Why are drugs tested on patients who have the particular disease?
To see if the drug actually treats the disease (cures illness)
Why is aspirin used as pain relief instead of willow bark?
The acetyl salicylic acid concentration in the aspirin is higher and more controlled. The bark has other compounds in it and is less known so there are side effects from it
What happens to the proteins of a digested microbe by a lymphocyte?
they are broken down by enzymes into amino acids
How do bacteria cause disease once in the body?
they reproduce rapidy and produce toxins
Why is it difficult to treat diseases caused by viruses?
- viruses live inside body cells as hosts
- difficult for the drugs to enter the body cells and would most likely kill them
- anitbiotics are ineffective against viruses
- viruses mutate frequently
Why can a person with a higher stroke volume, run fast?
- since more blood is sent to their muscles and lungs
- which supplies more oxygen and more glucose
- meaning a faster rate of respiration, transfering more energy for use
- making less lactic acid and less muscle fatigue and more muscle contraction
How are white blood cells adapted to perform their function?
- some white blood cells can change shape and engulf pathogens (undergo phagocytosis)
- some produce specific antibodies for the antigens of pathogens
- some produce ant-toxins to neutralise the toxins produced by pathogens
Why are clinical trials always carried out on healthy volunteers before patients?
To establish the toxicity of the drug and see it does not have harmful effects on a body which is working normally
What control variable must be used when clinically trialling for both the placebo and non-placebo groups?
the same age range used in groups
same gender used or mix of genders
Why does a Hymbridoma cell need to be made first in order to produce monoclonal antibodies?
- lymphcoytes can make antibodies but not divide
- tumour cells can divide but not make antibodies
- hybdridoma cells can therefore divide and make antibodies
- so produce many cells making monoclonal antibodies
