B2 - Keeping healthy Flashcards
(126 cards)
1
Q
What is the scientific name for microorganisms that cause disease and make us feel ill?
A
Pathogens
2
Q
When microorganisms get into the body, what do they do?
A
They reproduce quickly and cause symptoms of disease.
3
Q
What are the symptoms of an infectious BACTERIAL disease caused by?
A
Damage done to cells by microorganisms or the poisons (TOXINS) by the bacteria.
4
Q
What are 5 examples of bacterial diseases?
A
Bacterial meningitis
Tetanus
Salmonella
Tuberculosis (TB)
5
Q
What are the symptoms of a VIRAL disease caused by?
A
Damage to the cells as the viruses reproduce
6
Q
What are 4 examples of viral diseases?
A
Influenza (Flu)
The Common Cold
Measles
Chickenpox
7
Q
How do bacteria reproduce?
A
They reproduce by dividing into TWO.
8
Q
What is the type of asexual reproduction called that bacteria perform?
A
Binary fission
9
Q
What 2 specific conditions do bacteria need in order to reproduce?
Why do they need these conditions?
A
- A source of NUTRIENTS: for energy
2. WARM, MOIST conditions : so the chemical reactions inside them can take place
10
Q
What specific condition do viruses need in order to reproduce? How do they get this condition?
What can certain viruses do?
A
They need a HOST cell to reproduce.
They do this by entering the host cell and hijacking the cell’s mechanisms for making DNA and proteins and make copies of themselves.
Certain viruses can just easily reproduce inside of the body because there are lots of suitable conditions.
11
Q
How do viruses attack cells?
A
Copies of the viruses are released in very large numbers from the infected cell and go on to infect other cells and/or other people.
12
Q
What are the 4 stages to calculate the growth of a microorganism population?
A
- Work out how many hours the bacteria are reproducing for. Convert this to MINUTES.
- Divide the number of hours (in minutes, e.g. 120) by how many minutes one reproduction takes. This will give you the number of REPRODUCTION PERIODS.
- To work out the number of bacteria after the FIRST reproduction period, multiply the number of bacteria you started with by 2.
- Work out the number you’d have after the second reproduction (multiplying by 2 again).
- Do this until you’ve done ALL the reproduction periods (the answer you got from Step 2).
13
Q
What are 4 examples of the body’s EXTERNAL defences?
A
- Skin
- Saliva
- Tears
- Acid in the Stomach
14
Q
What is our body’s internal defence?
A
The Immune System
15
Q
What does the immune system use to defend the body?
A
White blood cells
16
Q
What are 2 features of white blood cells?
A
- Made in the bone marrow
- They are found in several types.
a. Some can engulf and digest invading microorganisms
b. Some can produce ANTIBODIES, which recognise and destroy invading microorganisms.
17
Q
What are ANTIGENS?
A
Chemicals on a pathogen’s surface that antibodies recognise as being foreign.
18
Q
Why is an antibody specific to one antigen?
A
Because the shape and structure of the antibody must lock in place with the antigen.
(e.g. a pathogen may have this as their antigen: →. A white blood cell may have this is their antibody: Y.)
19
Q
Once an antibody corresponding to an antigen locks on to it, what are the 2 series of events that happen?
A
- The White Blood Cell divides to produce many copies.
2. Each white blood cell produces many antibody molecules that lock on to the invading cells.
20
Q
What 3 things do different types of antibodies do?
A
- Destroys the invading microorganism
- Enables white blood cells to recognise the microorganisms as being foreign.
- Causes the microorganisms to clump together, meaning it is easier to engulf.
21
Q
After an infection clears up, what happens?
A
Memory cells remain in the bloodstream. These can produce large numbers of antibodies very quickly if the microorganisms enters the body again.
22
Q
At the point where memory cells produce antibodies, what would you classify a person to be?
A
IMMUNE to that particular antigen.
23
Q
What does a VACCINE contain?
A
A SAFE/WEAK form of the microorganism that causes a disease, so that you don’t become ill after receiving it.
24
Q
Once the vaccine has entered the bloodstream, what happens?
A
The immune system attacks the microorganism in the vaccine.
25
How does a vaccine work?
Once it has entered, the immune system would be 'fooled' that it is a real disease (when it's actually not) and so it would attack it. This means that antibodies are produced by the memory cells so that when the real disease returns, it can be easily eliminated. This therefore makes you immune.
26
What do some pathogens do that cause us to develop new vaccines?
Some pathogens CHANGE RAPIDLY (e.g. influenza) so new vaccines must be developed to tackle this.
27
How does an epidemic occur?
If a disease spreads rapidly through a population, for example in a city or a country.
28
How is it possible to avoid an epidemic?
It is necessary to vaccinate a HIGH PERCENTAGE of the population - this leads to HERD IMMUNITY.
29
What are 2 example of diseases that have been eradicated/reduced?
1. SMALLPOX - eradicated completely from the world.
| 2. MEASLES, MUMPS, RUBELLA (MMR) - reduced.
30
What is the longer-term aim in terms of vaccinations?
To eradicate certain diseases altogether.
31
Why must scientists test any new vaccines very carefully?
To check for any SIDE EFFECTS and to check that it is generally safe.
32
Why can side-effects be more severe in some people than in others?
GENETIC VARIATION
33
What can no type of medical treatment ever be?
COMPLETELY RISK-FREE
| but people often think the risk is higher than it is
34
Occasionally, what can a child potentially develop?
A minor adverse reaction (e.g. rash/fever)
35
In VERY RARE CASES, what could a child experience?
Very serious adverse reactions, e.g. anaphylaxis
| Any adverse reaction must be recorded and followed up.
36
Any RISKS of vaccination must be considered against the...?
The BENEFITS of the vaccination.
| Any vaccine generating an unusual number of adverse reactions will be quickly withdrawn.
37
What are antimicrobials?
Chemicals that INHIBIT the growth of microorganisms or kill them, without seriously damaging your own body cells.
They are effective against: bacteria, viruses, fungi.
38
Why are antimicrobials useful?
They can clear up infections that your own immune system is having trouble with.
39
What are antibiotics?
A type of antimicrobial that can kill BACTERIA, not viruses.
| These can treat illnesses like tuberculosis.
40
Like all organisms, what can microorganisms sometime develop (in terms of genetic information) ?
Random mutations in their DNA.
41
What can a random mutation in their DNA lead to for microorganisms?
They can lead to changes in the microorganism's characteristics. Sometimes, this means that the organism is less affected by a particular antimicrobial.
42
What is the scientific name that describes an organism that is less affected by an antimicrobial?
RESISTANCE
43
Why is resistance against antimicrobials advantageous for microorganisms?
They are better able to survive, even in a host who's being treated to get rid of the infection, and so it lives for longer and reproduces many more times.
44
What can an antibiotic resistance result in?
The gene for resistance can be passed on to lots of offspring - natural selection. This is how it spreads and becomes more common in a population of microorganism over a period of time.
45
How should antibiotics be used in order to reduce the likelihood of antibiotic resistance? Give 2 statements.
Antibiotics should be:
1. PRESCRIBED ONLY for more SERIOUS infections, when they are really needed.
2. COMPLETED, so that the bacteria causing the infection are killed completely.
46
What is an example of an antibiotic-resistant bacteria?
MRSA - it's resistant to most antibiotics and is a problem in many hospitals and drug companies.
47
What are the 4 stages of testing new treatments?
1. Vaccines are first tested for safety and effectiveness using human cells in a laboratory. This assesses the effect it has on real human cells.
2. Animals are used because they have similar composition of conditions in comparison to us. It must be tested on at least two different species (normally monkeys and rats). However, in some countries, it is illegal to do this.
3. HEALTHY Human volunteers (clinical trials) in order to test for safety. SICK human volunteers are also tested in order to test for safety and effectiveness.
4. The drug is published to the public. All known side-effects are recorded.
48
What are the three types of human trials?
Blind, Double-Blind, Open-Label
49
What is a Blind Trial?
The patient doesn't know which drug they are receiving but the scientists do.
50
What is a Double-Blind trial?
Neither the patient nor the scientist knows which drug is being given.
51
What is an Open-Label trial?
Both the scientists and the patients know which drug is used.
52
What is a Placebo?
A tablet/liquid made to look like the drug, but without the active ingredient.
53
What is one ethical issue related to a drug trial?
It must not disadvantage the patient. If evidence from the trial suggests the new drug is effective, it is offered straight away to patients receiving the placebo.
54
What are 2 reasons as to why some trials investigate the effects of the drug over a long period of time?
1. Side-effects may appear, or increase, over time.
| 2. The drug may become less effective.
55
Why is it important that human drug trials last a long time?
It takes a while for a drug to have the effect it was designed for, e.g. treating cancer. It's also important to find out if a drug has any side effects which may only appear after a long time.
56
What three 'components' make up the circulatory system?
Heart, blood vessels and blood.
57
What is the role of blood?
Carries nutrients and oxygen to the body's cells, and removes and carries waste products from the cells.
58
How is the blood bumped?
Around the body through blood vessels by the heart.
59
What is the heart normally classified as?
A DOUBLE PUMP - the right side is pumping de-oxygenated blood to the lungs to collect oxygen and remove CO2. The left side pumps the oxygenated blood around the body.
60
At the lungs, what does the de-oxygenated blood do?
It absorbs oxygen and gets rid of the Carbon dioxide.
61
What are the three types of blood vessels?
ARTERIES
CAPILLARIES
VEINS
62
In which direction do the arteries transport blood?
AWAY from the HEART under HIGH PRESSURE.
63
What is the structure of an artery like?
The walls are very thick, elastic and muscular to withstand the pressure.
64
In which direction do the capillaries transport blood?
They LINK arteries and veins.
65
What is the structure of a capillary like?
Walls are one-cell thick to allow the transfer of substances to and from cells.
It has a permeable wall so that substances can diffuse.
66
In which direction do the veins transport blood?
They COLLECT blood and RETURN it to the heart.
67
What is the structure of a vein like?
Walls contain elastic, muscular tissue but are thinner than those of arteries.
It has a larger lumen (hole) than capillaries and arteries.
The blood is under low pressure and veins have VALVES to prevent the backflow of blood.
68
Why do heart muscle cells need their own blood supply?
In order to deliver the nutrients and oxygen needed to keep the heart beating continually (and to remove waste products).
69
What is the name of the artery that run over the surface of the heart?
CORONARY artery
70
What can the coronary arteries become blocked by?
| What does this cause?
FATTY DEPOSITS.
| This will prevent the heart from receiving the oxygen it needs, leading to a heart attack.
71
What is 'heart rate' ?
The number of times your heart beats in one minute.
72
What is the heart rate measured in?
BPM (beats per minute).
73
What is our 'pulse rate' ?
The number of items an ARTERY pulsates in one minute.
74
What is the pulsation of an artery is caused by?
Blood being pumped through it by a heart beat, so you can measure your PULSE RATE to work out your HEART RATE.
75
When your heart muscle contracts, what happens to the blood?
Blood is forced out of the heart - this increases the pressure of your blood.
76
When your heart muscle relaxes, what happens to the blood?
The heart fills with blood and your blood pressure decreases.
77
What do blood measurements record?
The pressure of blood on the walls of an artery.
78
How are blood pressure measurements written?
With two values, e.g. 135 over 85.
79
What does the higher value in a blood pressure measurement represent? What does the lower value represent?
Higher value: the pressure of the blood when the heart CONTRACTS.
Lower value: the pressure of the blood when the heart RELAXES.
80
What can the heart rate and blood pressure be used for?
To check how HEALTHY patients are by COMPARING their measurements against NORMAL measurements.
81
What are normal measurements usually represented as?
| Why is this?
A range of values
| Because individuals vary, e.g. a normal resting heart rate for an adult is between 60 and 100 beats a minute.
82
What can high blood pressure do to the walls?
It can damage the walls of the arteries and make them more likely to develop fatty deposits and get narrower. It also puts a strain on the heart.
83
If a fatty deposit breaks through the inner lining of an artery, what might form?
BLOOD CLOT
84
What can the blood clot do in an artery?
Block it completely, or it could break away and block a different artery.
85
If a coronary artery is completely blocked, what would happen?
An area of the heart muscle will be totally cut off from its blood supply, receiving no oxygen. This causes a heart attack (which leads to death).
86
What does a high blood pressure increase the chance of?
Strokes and heart attacks
87
What can a low blood pressure cause?
Dizziness and fainting
88
What is blood pressure measured in?
millimetres of mercury (mm Hg).
89
What is the NORMAL resting heart rate (the heart rate when a person is relaxed) for a teenager?
What is it for an adult?
70-100 bpm = Normal for teenagers
| 50 - 70 pbm = good level of fitness for an adult
90
What can the misuse of drugs (e.g. ecstasy, cannabis, nicotine and alcohol) contribute to?
It can have an adverse effect on health, including blood pressure and heart rate, increasing the risk of a heart attack.
91
What are 4 lifestyle factors that INCREASE the risk of heart disease (i.e. Coronary Heart Disease (CHD) ) ?
1. Poor diet
2. Smoking
3. Stress
4. Misuse of drugs
5. Excessive alcohol drinking
92
How can a poor diet increase the risk of heart disease?
Cholesterol makes up a large part of the fatty deposits that form in arteries. This means that if the blood cholesterol is high, then the risk of heart disease is increased.
High blood cholesterol level is linked to eating foods high in saturated fat, e.g. fatty meats and cheese.
A diet high in salt also increases the risk of heart disease because it increases blood pressure.
93
How can smoking increase the risk of heart disease?
Carbon Monoxide (found in cigarettes) reduces the amount of oxygen the blood can transport. If heart muscle doesn't receive enough oxygen, it can lead to a heart attack.
Nicotine also increases heart rate, which leads on to increased blood pressure, which increases the risk of heart disease.
94
How can stress increase the risk of heart disease?
If a person is stressed for a long period of time it can increase their blood pressure and so increase the risk of heart disease.
95
How can the misuse of drugs increase the risk of heart disease?
Drugs like ecstasy/cannabis can also increase the risk of heart diseases by causing an increase in heart rate, which increases blood pressure.
96
How can excessive alcohol drinking increase the risk of heart disease?
It INCREASES BLOOD PRESSURE.
97
What can reduce the risk of developing heart disease?
| Why?
Regular moderate exercise - it burns fat, preventing it building up in the arteries. Exercise also strengthens the muscle.
98
How can a healthy diet, low in saturated fat, reduce the risk of heart disease?
It lowers blood cholesterol.
99
Where is heart disease more commonly found in?
| Why?
Industrialised countries, e.g. the UK and USA.
This is mainly because people in these countries can afford a lot of high-fat food and often don't need to be very physically active.
100
Other than lifestyle/environmental factors, what can also contribute to a person's chance of having heart disease?
Genetic factors - members of families that have a history of heart disease need to lower the risk factors.
101
What is epidemiology?
The study of patterns of diseases and the factors that affect them.
102
Which three studies are carried out through epidemiological studies?
1. Samples of individuals who are matched on as many factors as possible and differ only in the factor being investigated, e.g. smokes and non-smokers, drug users and non-drug users.
2. On individuals CHOSEN AT RANDOM
3. Investigate whether the genes carried by individuals affect the risk of suffering from particular health problems
103
What is homeostasis?
The maintenance of a CONSTANT, INTERNAL environment.
104
Why must the conditions inside of our body, even when the external environment changes, must be kept steady?
Because all your cells need the RIGHT conditions in order to FUNCTION properly.
105
What are 5 examples of factors that must be kept at values within a very narrow range for the body to function?
1. Temperature
2. pH
3. Levels of sugar
4. Water
5. Salt
106
What does homeostasis involve the communication of?
The nervous and hormonal systems.
107
How do our bodies respond to changes?
Using 'automatic control systems' throughout the body.
108
How does the system involved in homeostasis work?
1. RECEPTORS detect the change in the environment, e.g if the level is too high or too low.
2. PROCESSING CENTRES receive information and coordinates responses automatically.
3. EFFECTORS produce a response which COUNTERACTS the change, e.g. if the level is too high = level decreases, if the level is too low = level increases
109
What is Negative Feedback?
When the level of something (e.g. water/temperature) gets too high or too low, your body uses this mechanism to BRING IT BACK TO NORMAL.
110
Why is a balanced water level important?
So that it maintains the concentration of its cell contents at the CORRECT LEVEL for CELL ACTIVITY. So your body needs to balance the inputs and the outputs.
111
What are 3 ways in which water becomes an INPUT?
1. Drinking
2. Eating
3. Respiration
112
What are 3 ways in which water becomes an OUTPUT?
1. Sweating
2. Breathing
3. Faeces/urine
113
If the blood plasma is too concentrated, what will happen within the cells?
The cells will LOSE water.
114
If the blood plasma is too dilute, what will happen within the cells?
The cells will ABSORB water and BURST.
115
What are 3 ways in which kidneys play a major role in balancing levels of certain factors?
1. They filter small molecules from the blood, including water, sugar, salt and waste.
2. They REABSORB various things, e.g. ALL the sugar, as much salt and water as the body requires, etc.
3. Whatever isn't reabsorbed forms urine, which is excreted by the kidneys and stored in the bladder.
116
In general, how do the kidneys balance water levels?
By producing DILUTE or CONCENTRATED urine.
117
What does the concentration of urine depend on?
The concentration of the blood plasma.
118
Which 3 main factors affect the concentration of urine?
1. External temperatures - this affects the amount you sweat. Sweat contains water so this causes WATER LOSS. This means when it's hot the kidneys will REABSORB more water back into the blood. This leaves only a small amount of water - so only a SMALL AMOUNT of a quite CONCENTRATED urine will be produced.
2. Exercise - this makes you hotter, so you sweat to cool down. This produces the same affect as heat (a concentrated, small volume of urine).
3. Intake of fluid and salts - not drinking enough water or eating too much salt will produce concentrated urine (because there will be little excess water to 'dilute' the other wastes). Drinking lots of water will produce lots of dilute urine. This makes you dehydrated.
4. Ecstasy (MDMA) causes the kidneys to produce very small volumes of concentrated urine. The body's cells will swell with water.
119
What is the name of the hormone that controls the concentration of urine?
Anti-diuretic hormone (ADH)
120
What gland releases ADH into the bloodstream?
ADH is released into the bloodstream by the PITUITARY GLAND.
121
The secretion of ADH is controlled by what mechanism?
NEGATIVE FEEDBACK
122
What are the stages of regulation of a HIGH concentration of water?
1. Receptor in the brain detects that the water content is TOO HIGH.
2. Processing centre in the brain receives the information and coordinates a response.
3. The PITUITARY GLAND releases LESS ADH so the KIDNEYS REABSORB LESS WATER.
123
What are the stages of regulation of a LOW concentration of water?
1. Receptor in the brain detects that the water content is TOO LOW.
2. Processing centres in the brain receives the information and coordinates a response.
3. The PITUITARY GLAND releases MORE ADH, so the KIDNEYS REABSORB MORE WATER.
124
Which two things affect ADH Production?
1. Alcohol
| 2. Ecstasy
125
How does alcohol SUPPRESS ADH Production?
1. Drinking urine results in a larger amount of MORE DILUTE urine (than normal) being produced.
2. Alcohol SUPPRESSES (prevents the development) of the production of ADH, so the kidneys will reabsorb less water.
3. This means MORE WATER passes out of the body as URINE, which can cause DEHYDRATION. This can be harmful to your health (it can cause dizziness which could lead to death)
126
How does ecstasy INCREASE ADH Production?
1. Taking ecstasy can result in a SMALLER AMOUNT OF MORE CONCENTRATED urine (than normal) being produced.
2. Ecstasy causes the production of ADH to INCREASE, so the kidneys will reabsorb MORE WATER.
3. This means that LESS WATER can pass out of the body as urine.
