B2 - Keeping Healthy Flashcards
What are infections caused by?
Microorganisms damaging body cells or producing poisons (toxins) that harm cells.
What can infections be treated by?
Drugs called antimicrobials (e.g. antibiotics)
True or False?
All antimicrobials kill microorganisms.
False - Many antimicrobials kill the microorganisms but some just block or slow down their action.
Many antimicrobials kill the microorganisms but some just block or slow down their action.
What is this called? (HT)
Inhibition.
What are 3 types of microorganisms that cause infections? Give examples of each and state how each type can be treated.
- Bacteria, e.g. bubonic plague, tuberculosis (TB) and cystitis. treated by antibiotics.
- Fungi, e.g. athlete’s foot, thrush and ringworm. Treated by anti-fungal medicine and antibiotics.
- Viruses, e.g. Asian bird flu, common cold, HIV, measles and smallpox. Very difficult to treat as antibiotics don’t work on viruses
Where can microorganisms be found?
On any surface, in food and drink, in water and in the air we breathe.
What three conditions are ideally needed for microorganisms to grow rapidly?
- Warmth
- Plenty of nutrients
- Lots of moisture
Fill in the gaps.
Once in your body, harmful microorganisms reproduce very _______ - some populations can double as fast as every _______ minutes.
- rapidly
- 20
Symptoms of an illness only show when there’s a significant amount of infection. How are the symptoms caused?
By microorganisms damaging infected cells, e.g. bursting the cells or producing harmful toxins.
If microorganisms get into your body, what is activated?
The immune system
When microorganisms get into your body and the immune system is activated, what type of blood cell plays a major role in the body’s response?
The white blood cell
Two types of white blood cells are released when the body’s immune system is activated. What do the two types of white blood cells do?
One type of white blood cell engulfs and destroys the microorganisms, and the other makes antibodies.
How does a white blood cell digest microorganisms?
When microorganisms invade the body, the white blood cells find them and engulf them. They then ingest the micro-organism and digest and destroy them.
What are antigens?
Markers on the surface of the microorganism.
What happens when white blood cell are producing antibodies?
The white blood cells become sensitised to the antigens on the surface of the microorganism and produces antibodies that lock onto the specific shape of the microorganism’s antigens. This causes the microorganisms to clump together, so that other white blood cells can digest them.
Why do microorganisms have uniquely-shaped antigens on their surface?
Because different microorganisms cause different diseases.
How does the process of producing antibodies help the body’s immune system?
Some white blood cells act as ‘memory cells’ once the infection has been destroyed, so that when those microorganisms enter the body again, the immune system knows how to fight it off. This is natural immunity.
What happens when an individual is vaccinated?
A weakened/dead strain of the microorganism is injected into the system. White blood cells produce the antibodies to fight it off and the memory cells know how to fight that type of microorganism off when the real version enters the system.
True or False?
Vaccinations are completely safe all the time.
False - Vaccinations are never completely safe and can produce minor side effects, such as rashes. Extreme side effects are rare, but the vaccination usually carries less risk than the disease.
Why might some people be more affected by a vaccination than others?
Because of genetic variation.
Why do some vaccines have to be redeveloped regularly?
Because microorganisms mutate (randomly genetically change) to produce new varieties/strains.
True or False?
The more who say no to having a vaccination, the smaller the chance of a disease outbreak and a slower spread of disease.
False - The more who say no to having a vaccination, the more likely it is that there will be a disease epidemic/outbreak and the faster it will spread.
Why is it important to vaccinate as many people as possible? (HT)
Because it prevents a disease epidemic
What will happen to a population of which more than 95% are vaccinated against a disease?
The unvaccinated will be protected as well, as the risk of contact with an infected person is small.
What will happen to a population of which less that 95% are vaccinated against a disease?
There is a greater chance of contact with infected people and therefore the likelihood of a disease outbreak/epidemic is much higher.
Over time, bacteria and fungi can become _________ to antimicrobials.
Resistant.
When random mutations occur in genes of microorganisms, what can happen? (2 things) (HT)
- New strains develop
- These are less affected by antimicrobials, so they can reproduce and pass on their resistance.
Complete the sentence.
As varieties of bacteria and fungi become resistant…
…there are fewer ways to defeat them.
What two measures can be put in place to help prevent antimicrobial resistance?
- Doctors should only prescribe them when absolutely completely necessary
- Patients should always complete the course of medication prescribed to them.
What are new drugs tested for before they can be used?
Safety and effectiveness
What are some advantages of testing on human cells grown in a laboratory?
- Shows if the drugs are effective
- Shows if the drugs will damage cells
- No people or animals are harmed
What are some disadvantages of testing on human cells grown in a laboratory?
- Doesn’t show the effects on the whole organism
- Some might say that growing human cells is wrong/unethical
What are some advantages of testing on animals in a laboratory?
- Shows if the drugs are effective within whole body conditions
- Shows if drugs are safe for the whole body
What are some disadvantages of testing on animals in a laboratory?
- Animals can suffer and die (unethical issues)
- Animals may react differently to humans
Who are clinical trials carried out on?
- Healthy volunteers to test for safety
- People with the illness to test for safety and effectiveness
What is a placebo?
A harmless drug
What does using a placebo in a clinical trial mean?
The patient isn’t treated for the problem - you haven’t got any false reactions.
What do clinical trials compare the effects of? (HT)
Old and new drugs
What happens in a ‘blind trial’? (HT)
The patients do not know which drugs they are given but the doctor does. If the patient knows, they might give biased information.
What happens in a ‘double blind’ trial? (HT)
Neither the patient or the doctor know which drugs is used.
What can you say about the results obtained from a ‘double blind trial’? (HT)
Results should be very accurate, due to removing the bias.
What happens in an ‘open-label trial’? (HT)
Both the doctor and the patient know that they are using a new treatment. This is used when the new treatment is very similar to the original, or when a drug is being compared to physical therapy.
Why is a ‘long-term trial’ important? (HT)
These are important for ensuring that there are no harmful side effects and to make sure that the treatment continues to be effective.
What type of microorganism can’t be treated with antibiotics?
Virus
Why are microorganisms like MRSA often called ‘superbugs’?
They are resistant to antibiotics.
Why is the heart called a ‘double pump’?
It pumps blood from its right side to the lungs and also pumps blood from its left side to the rest of the body
The heart pumps blood to provide body cells with what?
Nutrients and oxygen
The heart pumps blood to remove what from the body cells?
Waste products
What is the heart made up of?
Muscle cells that need a blood supply from the coronary artery to function properly.
What are the three main types of blood vessels?
Arteries, Veins, Capillaries
What is the structure of an artery like?
An artery has a thick, elastic, muscular wall to cope with the high pressure in the vessel.
What is the function of an artery?
Arteries carry blood away from the heart towards the organs in the body.
True or False?
Substances from the blood can pass through the walls of an artery.
False - Substances from the blood cannot pass through artery walls.
What is the function of veins?
Veins carry blood from the organs back to the heart?
Can substances pass through the walls of a vein?
No
What is the structure of a vein like?
A vein has a thinner wall than an artery and has less elastic muscular fibre due to the lower pressure in the vessel.
Why do veins have pocket valves along their length?
To keep blood flowing in the right direction.
What are capillaries?
Very narrow vessels that carry blood between arteries and veins and through the organs of the body.
a) Can substances pass through the walls of capilleries?
b) Why?
a) Yes.
b) Capillaries have walls made of a single layer of cells. It is here that substances are exchanged between blood and body cells.
What is heart disease?
A structural or functional abnormality that can lead to a heart attack.
What is a heart disease usually caused by?
Either lifestyle factors or genetic factors
True or False?
Heart disease can sometimes be caused by infection.
False - Heart disease is not caused by infection.
Why is heart disease more common in the UK than some non-industrialised countries?
As a result of lifestyle differences in their populations.
When does a heart attack occur?
When fatty deposits build up in blood vessels supplying the heart. Blood flow is restricted and the muscle cells in the heart don’t get enough oxygen and nutrients.
What are some lifestyle factors that can lead to heart disease? Why do they increase the risk of heart attack?
Poor diet, smoking, stress, misuse of drugs (such as ecstasy, cannabis), misuse of alcohol, can all affect blood pressure and heart rate (pulse rate) which increase the risk of a heart attack.
What are 3 precautions someone could take against heart disease?
- Regular exercise (e.g. 20 minutes brisk walking every day)
- Not smoking
- Maintaining a healthy weight and reducing salt intake
What can heart rate (pulse rate) and blood pressure be used to monitor?
The risk of heart disease.
Blood pressure is given in two types of numbers. What are they?
- Higher number (obtained when the heart is contracting)
- Lower number (obtained when the heart is relaxing)
What can high measurements of blood pressure and or heart rate (pulse rate) mean?
They can indicate a high risk of heart disease.
The human body has an input and an output of water. Explain in what ways water is gained from (2 things) and lost through (3 things).
Water is input (gained) from:
- Food and drinks
- Respiration
Water is output (lost) through:
- Sweating
- Breathing
- Excretion of faeces and urine
Why does your body have to balance the input and output of water?
To ensure that there’s enough water inside cells for cell activity to take place.
What is the function of the kidneys?
They balance the water level in your body, and also help to balance waste and other chemicals in the blood.
Both hormonal and nervous systems are involved in maintaining the stability of the internal environment of the body. What is this process called?
Homeostasis.
How are the body’s water levels monitored?
- Receptor cells in the brain monitor the water level
- The brain then processes this information and coordinates the response to the effector organ
- The pituitary gland is an effector which produces the response
- This results in a hormone being released to affect the kidneys and the amount of water that’s released or retained in the blood.
When the water level is too high in your body, how do the kidneys respond?
The kidneys reabsorb less water and a large amount of dilute urine is produced.
When the water level is too low in your body, how do the kidneys respond?
The kidneys reabsorb more water and a small amount of concentrated urine is produced.
The amount of water that needs to be reabsorbed into the blood plasma depends on what 3 factors?
- The external temperature
- The amount of exercise taken
- The fluid intake
When salt levels in your body increase, what does your body do?
The body removes any excess salt by producing dilute urine. This means you need to take in more fluids to maintain a balanced water level.
Alcohol can lead to dehydration.
Why is this?
Because alcohol causes a large amount of dilute urine to be produced, which can adversely affect overall health, which can lead to dehydration.
True or False?
Ecstasy causes a large amount of more concentrated urine to be produced.
False - Ecstasy causes a small amount of less dilute urine to be produced.
The concentration of urine is controlled by what hormone? (HT)
Anti-diuretic hormone (ADH)
How is ADH released into your blood? (HT)
Via. the pituitary gland.
Is the body’s control of water balance an example of a negative or a positive feedback system? (HT)
A negative feedback system.
What is a negative feedback system? (HT)
Where one system is the reverse to another in order to maintain a steady state.
When your blood water level becomes too high, what happens?
- Receptors in the hypothalamus detect a decrease in salt concentration. No stimulus is sent to the pituitary gland.
- Less ADH is secreted into the blood
- Your kidneys become less permeable, so less water is reabsorbed.
- Your bladder fills with a large quantity of dilute urine.
When your blood water level becomes too low, what happens?
- Receptors in the hypothalamus detect an increase in salt concentration. A stimulus is sent to the pituitary gland. Thirst is stimulated to encourage drinking.
- More ADH is secreted into the blood
- Your kidneys become more permeable, so water is reabsorbed.
- Your bladder fills with a small quantity of concentrated urine.
What can affect the production of ADH?
Drugs like alcohol and ecstasy.
How can alcohol affect the production of ADH?
Alcohol causes ADH to be suppressed, so more water leaves the body in the urine.
How can ecstasy affect the production of ADH?
Ecstasy causes too much ADH to be produced, so too much water remains int he blood. Osmosis then causes the water to leave the blood, causing brain cells to swell and burst.
Suggest some lifestyle factors that are likely to cause premature death.
- Alcohol
- Poor diet
- Smoking
- Stress
- Genetics
- Drug abuse
Vaccines prevent disease. What is contained in a vaccine? Is it:
a) Antibiotics
b) A weakened or dead strain of the disease-causing microorganism
c) An active strain of the disease-causing microorganism
d) Antibodies
b) A weakened or dead strain of the disease-causing microorganism
Why can vaccines never be completely safe?
There is always a small chance of side effects occuring
Why do new vaccines have to be developed regularly for diseases such as flu?
The virus causing the disease mutates, producing a new strain that’s unaffected by the current vaccine.
In a trial to test a new drug it was found that, in most cases, the test sample of patients who had been ill had shown a marked improvement in their condition after a course of treatment.
a) We can say this shows a
i - correlation?
ii - relationship?
between the treatment and its effect.
b) From the information above, the drug
i - definitely causes
ii - possibly does not cause
the outcome effect.
A second group of patients was given a placebo in place of the drug. No members of this group showed any improvement in their condition.
c) A placebo is a
i - similar drug
ii - harmless drug
d) Using all the information in this question, it can be said that it is highly likely that the drug
i - causes
ii - does not cause
the outcome effect.
a) i = correlation
b) ii = possibly does not cause
c) ii = harmless drug
d) i = causes
In the winter, we urinate more because we don’t lose water in sweating. The blood water level gets very high. Explain how this is brought about it in the body.
Receptors in the hypothalamus cause less ADH production, so the kidneys reabsorb less water and larger amounts of urine are produced.
