B2-Keeping Healthy

How are symptoms caused?Give examples.

1)cell damage, e.g. malaria parasites.2)Toxins-some bacteria produce protein damages material that holds cells together, e.g. Staphylococcus can cause food poisoning. Others produce toxins that poison cells, causing fever or inflammation e.g.E-coli.

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What conditions do bacteria need in order to multiply?

Source of nutrients (for energy) and warm, moist conditions. Lots of places like this in body, so few bacteria can soon become a colony.

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Which type of microorganism needs other cells to reproduce?Why?

Viruses because they use parts of other cells to make copies of themselves.

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What is the role of the immune system?

To deal with infectious microorganisms that enter the body.

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What does an immune response always involve?

White blood cells (there are several types).

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Describe what happens when something enters the body?

1)it should be picked up straight away by certain white blood cell type.2)These white blood cells able to detect 'foreign' things e.g. microorganisms.3)The engulf and digest them.4)White blood cells non-specific, attack anything not meant to be there

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What are antigens?

Substances that trigger immune responces- they're usually protein molecules on the surface of microorganisms.

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What do antibodies do?

Recognise foreign microorganisms and latch onto them. Then do one of three things.

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What are the three things that antibodies do?

1)Mark the microorganisms so other white blood cells can engulf and digest it.2)Bind to and neutralise viruses or toxins.3)Attach to bacteria and kill them.

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What does a white blood cell do when it recognises the antigens on a microorganism?

It divides to make more identical cells, which will make lots of the right antibody to fight the infection.

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What are memory cells and what do they do?

When some white blood cells stay after the infection has gone. They can reproduce very quickly if same antigen enters body again, so won't feel ill-known as immunity.

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Describe vaccinations.

1)dead or inactive microorganisms injected-carry same antigens.Body produces antibodies to attack them- even though microorganism is harmless.2)Body produces memory cells that recognise antigens of the microorganism and stays in blood.On next card..

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Describe vaccinations continued.

3)If live microorganisms of same type enter body, memory cells can rapidly mass produce antibodies.4)Normally means can get rid of microorganism before they make you sick.

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What are epidemics?

Big outbreaks of disease.

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How can epidemics be prevented?

By vaccinating a large percentage of the population. If large number of people vaccinated, diseases can spread quickly- lots of people ill at same time.But, if most people are vaccinated even those who aren't are less likely to get the disease.

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Why do vaccines and drugs have different effects on different people?

Because of genetic differences.For example, anesthetics stop people from feeling pain but genetic differences means length of time anesthetic works is different.

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What are antimicrobials?

Chemicals that inhibit the growth of microorganisms or kill them, without seriously damaging body cells.

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Why are antimicrobials useful?

for clearing up infections that your own immune system is having trouble with.

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Give an example of an antimicrobial.

Antibiotics.

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What types of microorganism do antibiotics not kill?

Viruses- flu and colds are types of viruses so cannot be treated with antibiotics.

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Describe antimicrobial resistance.

1)Microorganisms can develop DNA mutations.2)Mutations can lead to changes in characteristics.Sometimes mean microorganism is less affected by particular antimicrobial.3)big advantage as they can survive for longer and reproduce more.(Next card)

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Antimicrobial resistance continued.

4)Leads to gene resistance being passed on to offspring(natural selection).Becomes more common in population over time.5)Resistant microorganisms more common- can't easily be gotten rid of.

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Why is it important to only take antibiotics when you need to?

1)More often antibiotics are used, bigger resistance is.2)If thy aren't benefiting you, pointless to take them and it could be harmful to everyone else.

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Why is it important to take all antibiotics prescribed to you?

It can increase the risk of antibiotic resistant bacteria emerging.

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Where are drugs first tested?

In a laboratory.

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Explain how drugs are tested in a lab?

1)Drugs developed using human cells grown in a lab-can measure effect on real human cells.2)But, it can't recreate conditions of whole human body, can't be sure it actually works.3)All new drugs must be tested on two animals.(next card).

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Drugs in a lab continued.

4)Animals tested on usually rats and monkeys. Mammals have similar systems to humans so tests give indications of how drug will effect body.5)If drug causes serious problems to animals, testing unlikely to go further than lab.

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How are drugs tested after they've been tested in a laboratory?

On humans in clinical trials.

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Describe clinical trials.

1)Tested on healthy volunteers to make sure there are no harmful side effects-sick people more vulnerable to damage.2)If results from healthy volunteers good, tested on sufferers, both for safety and effectiveness.(next card)

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Clinical trials continued.

3)Placebos used in human trials-to compare results.4)If drug works, results should show that those who took the drug have improved more than those who took placebo.

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What are the three types of human trials?

Blind trial, double blind trial and open-label trials.

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Describe blind trials.

When the patients don't know whether they have taken the actual drug or placebo. If they know they have the drug, they may feel better for psychological reasons.But, if they know they have the placebo they might not feel better even if they're better

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Describe double blind trials.

The sientists and patient don't know who has taken the actual drug or placebo until the end. This is so scientists aren't subconsciously influenced by their knowledge.

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Describe open-label trials.

Both scientists and patients are aware of the treatments used. Usually used if the illness is terminal.

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Why do human drug trials last a long time?

Because it takes while for the drug to have the effect it was designed for. Also it's important to find any long term side effects.

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How is blood circulated around the body?

Blood vessels.

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What is carried in the blood to body cells?

Oxygen and nutrients.

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What is carried away from body cells as waste?

Carbon dioxide.

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What is the heart?

A pumping organ that keeps blood flowing through the vessels.

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Describe the double pump.

The right side pumps deoxygenated blood to the lungs to collect oxygen and remove carbon dioxide. The left side pumps oxygenated blood around the body.

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What is the heart made up off?

Heart cells that beat constantly. They need their own blood supply to deliver nutrients and oxygen to keep the heart beating.

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How is blood supplied to the heart?

By the coronary arteries,which branch from the aorta (the biggest artery in the body).

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Name the three major types of blood vessel.

Arteries, veins and capillaries.

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Describe arteries.

1)Carry blood away from heart to body cells(including heart muscle).2)Comes out of heart at high pressure, so artery walls are strong and elastic, much thicker than vein walls.

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Describe veins.

1)Carry blood back to heart.2)Blood at lower pressure in veins so walls aren't as thick.3)Have a bigger lumen than arteries to help blood flow easily.4)Valves to keep blood flowing in right direction.

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Describe Capillaries.

1)Branches of tiny arteries.2)Carry blood really close to every cell to exchange substances with them.3)Have permeable walls, so substances can diffuse.4)Supply nutrients and oxygen, take away CO2.5)Walls one cell thick,increases rate of diffusion.

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What is your heart rate?

The number of times your heart beats in one minute, it's measured in beats per minute (BPM).

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What is pulse rate?

The number of times an artery pulsates in one minute.

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What is the pulsation of an artery caused by?

Blood being pumped through it by a heart beat, so you can measure your pulse rate to work out your heart rate.

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Describe blood pressure.

1)When heart muscle contracts, blood forced out of heart, this increases blood pressure.When heart muscle relaxes heart fills with blood and blood pressure decreases.

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How is a blood pressure reading taken?

Taking a reading of the pressure of blood against the walls of an artery.

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Why do blood pressure measurements have two values?

e.g.135 over 85. Higher value is when heart contracts and lower value is heart when it relaxes.

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What is blood pressure used for?

To see how healthy a person is by comparing their measurements to normal measurements.

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What does high blood pressure increase the risk of?

Heart disease.

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Explain how high blood pressure increases the risk of heart disease.

1)inner lining of artery usually smooth and unbroken but high blood pressure can damage it.2)Fatty deposits can build up in damaged areas of arteries-restrict the flow of blood and cause blood pressure to increase.Next card.

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Blood pressure and heart disease continued.

3)If fatty deposit breaks through artery inner lining, blood clot may form around it.4)Blood clot could block artery or could break away and block a different one.5)If coronary artery gets blocked, heart gets no oxygen-causes heart attack(fatal)

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What are the five factors that can increase the risk of heart disease?

Poor diet,smoking,stress,misuse of illegal drugs, excessive alcohol drinking.

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How does poor diet increase the risk of heart disease?

1)cholesterol makes up large part of fatty deposits.2)If blood cholesterol level is high, chance of heart disease increases.3)High blood cholesterol linked to foods high in saturated fat.4)Diet high in salt increases risk of heart disease.

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How does smoking increase the risk of heart disease?

1)Both carbon monoxide and nicotine increase risk of heart disease.2)Carbon monoxide reduces amount of oxygen blood can transport, if heart doesn't get enough oxygen,can lead to heart attack.3)Nicotine increases heart rate-means heart contracts more.

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How does stress increase the risk of heart disease?

1)If someone is stressed for a long period of time, their blood pressure increases and so can the risk of heart disease.

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How does misuse of illegal drugs increase the risk of heart disease?

Drugs like ecstasy and cannabis cause an increase in heart rate, which increases blood pressure.

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How does excessive alcohol drinking increase the risk of heart disease?

Increases blood pressure, so increases the risk of heart disease.

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What reduces the development of heart disease?

Regular exercise-it burns fat and strengthens heart muscles.

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What is epidemiology?

The study of patterns of diseases and the factors that can affect them.

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How are epidemiological studies used?

1)To help identify lifestyle risk factors. 2)Involve large scale genetic studies to identify genetic risk factors.

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What does homeostasis mean?

Maintaining a constant internal environment.

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Explain homeostasis.

1)it's about balancing inputs and outputs.2)Conditions in body need to stay steady as cells need right conditions to function properly.3)Have many automatic control systems to regulate internal environment-both nervous and hormonal.Next card.

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Homeostasis continued.

4)There's a control system that maintains water content and body temperature.

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What are all control systems made up of?

Receptors, processing centres and effectors.

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What is negative feedback?

Counteracts change and keeps body's internal environment stable,

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What does a receptor do?

Detects a change in the environment.

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What does a processing centre do?

Receives the information and co-ordinates a response.

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What does an effector do?

Produces a response, which counteracts the change.

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Why is balancing water levels important?

Body needs to maintain the concentration of cell contents at correct level for cell activity, so body needs to balance inputs and outputs.

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Give examples of inputs.

Water from drinks, food and respiration.

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Give examples of outputs.

Water can be lost through sweating, breathing, in faeces and in urine.

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What do the kidneys do?

Play a vital role in balancing levels of water, waste and other chemicals in body.

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What do the kidneys do in order to balance water levels?

1)Filter small molecules from blood including water,sugar,salt and waste.2)They reabsorb all the sugar, as much salt and water as the body requires.Water absorption is controlled by hormone ADH.3)Whatever isn't reabsorbed forms urine.

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What does the concentration of urine depend on?

Concentration of blood plasma.

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How does external temperature effect the concentration of urine?

Temperature affects amount you sweat. Sweating causes water loss.Means that when it's hot more water is reabsorbed.Leaves only small amount of water, so only small amount of quite concentrated urine is produced.

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How does exercise effect the concentration of urine?

Exercise makes you hotter-sweat to cool down.Produces same effect as heat- concentrated, small volume of urine.

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How does intake of fluids and salt effect the concentration of urine?

Not drinking enough water or eating too much salt will produce concentrated urine.Drinking lots of water will produce lots of dilute urine.

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What is the concentration of urine controlled by?

A hormone called anti-diuretic hormone (ADH).

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What is the brains role in balancing water levels?

Brain monitors water content of the blood an instructs the pituitary gland to release ADH into blood according to how much it needed.

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What does the receptor do if there is too much water in the body?

Receptor in brain detects that water content is too high.

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What does the processing centre do if there is too much water in the blood.

Processing centre in brain receives information and coordinates a response.

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What does the effector do if there is too much water in the body?

The pituitary gland (effector) releases less ADH so kidneys reabsorb less water

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What are two drugs that affect ADH production?

Alcohol and ecstasy.

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How does ecstasy affect the production of ADH?

1)Alcohol results in larger amount of more dilute urine.2)Alcohol suppresses ADH production-less water reabsorbed.3)Means more water passes out of body as urine, can cause dehydration.

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How does ecstasy affect the production of ADH?

1)Result in smaller amount of more concentrated urine than normal.2)Causes production of ADH to increase so kidneys will reabsorb more water.3)Means less water can pass out of body as urine.

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B2-Keeping Healthy

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