CB5- Health, Disease And The Development Of Medicines

Question 1

What is health?

Answer 1

• a state of complete physical, mental and social well-being, not just the absorption illness or disease
• for example even if someone is physically fit- eating well, free from disease, getting regular physical activity- they may still be unhealthy due to poor mental health or social isolation

Question 2

What is disease?

Answer 2

• a condition where part of an organism does not function correctly, this is not the result of injury
• a disease can either be communicable- spread between individuals by pathogens or they can be non-communicable- diseases that cannot be transmitted between individuals and are caused by faulty genes or lifestyle

Question 3

What is a communicable disease?

Answer 3

• diseases that can be spread between individuals
• they are caused by pathogens

Question 4

What is a non communicable disease?

Answer 4

• non communicable diseases cannot be transmitted between individuals
• they are caused by problems in the body like faulty genes or lifestyle.

Question 5

How are diseases correlated with one another?

Answer 5

• if you are affected by one disease, it can make you more susceptible to others, this is because:
• one disease can damage the immune system, making it easier for other pathogens to cause diseases
• diseases can also damage the body’s natural barriers, and defences, allowing pathogens to get into the body more easily
• a disease scan stop an organ system from working effectively, making other diseases more likely to occur

Question 6

What are pathogens?

Answer 6

• pathogens are micro organisms such as viruses, bacteria, fungi and protists that cause communicable diseases

Question 7

Describe the disease cholera.

Answer 7

• the pathogen that causes cholera is a bacterium
• it is a communicable disease
• the symptoms/effects are diarrhoea
• it spreads via contaminated water
• to reduce cholera there must be clean water supplies

Question 8

Describe the disease tuberculosis.

Answer 8

• tuberculosis is caused by bacterium
• it is a communicable disease
• symptoms include coughing blood specks as it infects and damages lungs
• it spreads via air and wind by and infected coughs
• to reduce TB infected people should avoid crowded areas, practice good hygiene, live in well ventilated living spaces

Question 9

Describe the disease malaria.

Answer 9

• malaria is caused by a protist
• it is a communicable disease
• symptoms and effects include fevers and tiredness, as red blood cells are minimised in size and amount
• it spreads via mosquitos which are vectors(carriers) that will spread the protists onto humans, without being affected itself
• to reduce malaria use mosquito nets and insect repellant to prevent bites

Question 10

Describe chalara ash dieback.

Answer 10

• caused by fungus
• communicable disease between ash trees
• the symptoms and effects are early dying, loss of leaves and wounds on bark
• it is an airborne disease carried by the wind but also can be spread during the transportation of infected ash trees
• to prevent this you must remove young infected trees, restrict the import and movement of infected trees.

Question 11

What are STI’s and what are some important ones you need to know?

Answer 11

• sexually transmitted infections
• spread through sexual intercourse and contact
• notable STI’s include chlamydia and HIV

Question 12

What is HIV?

Answer 12

• HIV is a sexually transmitted virus
• it is the human immunodeficiency virus
• it infects and kills white blood cells which can affect the immune system and prevent it from functioning properly, since their immune systems can prevent them from secondary infections people with HIV often develop AIDS.
• it is spread via infected bodily fluids (blood, semen, vaginal fluids)
• to prevent aids: use condoms, drug users shouldn’t share needles, medication can reduce the risk, screening allows early diagnosis for treatment

Question 13

What is AIDS?

Answer 13

• AIDS is a disease caused by HIV. HIV damages the immune system, causing it not to be able to defend against secondary infections
• the infected persons immune system deteriorates and eventually fails, this causes the person to be very vulnerable to other pathogens which could infect them
• this means that even mere colds can have a severe effect on people with HIV

Question 14

What is chlamydia?

Answer 14

• chlamydia is a sexually transmitted bacterial infection
• while it’s a bacterium, it behaves in a similar way to a virus by infecting a host cell and reproducing
• it can result in infertility in both men and women
• it is also caused by bodily fluid contact
• to prevent: wear a condom, get regular screening for early treatment, avoid sexual contact- abstinence

Question 15

What is a physical barrier? +examples

Answer 15

• skin is the main example of a physical barrier, pathogens could only cross via vectors or wounds since it is difficult to get past it.
• if there were to be a wound however, blood platelets would cause the blood to clot and the opening, preventing excessive bleeding and pathogens from entering.
• mucus in the nose and airways in the lungs trap particles that contain pathogens
• cilia- also lines airways and are hairlike structures that will take mucus(with the trapped pathogens) to the back of the throat where it can be swallowed.

Question 16

What is a chemical barrier?+examples

Answer 16

• hydrochloric acid in the stomach can kill pathogens that have been swallowed while being trapped in mucus
• lysozyme is an enzyme that that breaks down the cell walls of some bacterium’s and are able to kill them, they are secreted in tears, saliva and mucus, it is a chemical defence because it reacts with substances in the pathogen in order to kill them

Question 17

What is the function of the immune system?

Answer 17

• if pathogens were to enter the body after overcoming all the physical and chemical barriers, then the immune system would become active and destroy the pathogens.

Question 18

What is the immune system made up of?

Answer 18

• white blood cells- which are able to detect pathogens and kill them
• white blood cells known as lymphocytes are greatly involved in the immune response as they produce anti bodies that are able to bind onto the anti gens on pathogeths and kill them
• phagocytes also play a crucial role as they are non-specific white blood cells which trap, engulf and digest pathogens
• phagocytosis is often the first process to happen as it is non specific to the pathogen, then (it’s a general defence mechanism) and then lymphocytes are used for highly specific targeted responses.

Question 19

What is the function of lymphocytes?

Answer 19

• white blood cells known as lymphocytes are greatly involved in the immune response
  All pathogens have antigens on their surfaces, when lymphocytes come across these pathogens they are able to produce antibodies which are complimentary to these antigens, the anti bodies can match its surface shape to the antigens, and then bind onto them.
• the lymphocyte is now activated and can divide rapidly to produce lots of other identical lymphocytes with the same antibody to now destroy the pathogens all throughout the body
• after all the pathogens are killed some lymphocytes with anti bodies that still match the former antigens of the pathogen remain in the blood and are known as MEMORY LYMPHOCYTES

Question 20

What is the significance of memory lymphocytes?

Answer 20

• since memory lymphocytes remain in the blood, containing the same antibody needed to fight a specific pathogen, if it were to enter the body again the memory lymphocytes will have a faster secondary response, making you immune to that specific pathogen
• the secondary response may be so fast that it comes into action before symptoms are even present

Question 21

What is phagocytosis?

Answer 21

• phagocytosis is when phagocytes are able to detect pathogens in the body and engulf and digest them
• phagocytosis is non specific so it is a general mechanism of defence against all pathogens

Question 22

What is immunisation?

Answer 22

• this is when people can get vaccinated against some diseases to avoid getting I’ll
• this involved infecting a weaker, inactive version of disease, usually some weak pathogens that will not cause a huge effect
• even though these pathogens are not active, they will still carry antigens so your body will formulate a response with lymphocytes which will produce antibodies to kill the pathogen
• the antibodies from this will remain in the blood as memory lymphocytes so if the same type of disease/pathogen were to enter the body again, the body would have a very fast immune response, stopping the illness

Question 23

What are antibiotics and how do they work?

Answer 23

• used to treat bacterial infections
• it does this by inhibiting processed in bacterial cells, but not the host organisms
• it can do by inhibiting the bacterial cell wall, this will have no effect on the host organism as animal cells do not have cell walls
• some issues with antibiotics can be antibiotic resistance

Question 24

Are antibiotics effective against viruses?

Answer 24

• antibiotics don’t destroy viruses as they attach themselves to host cells and it would be very difficult to just destroy the virus without destroying the host cell

Question 25

How are new drugs developed?

Answer 25

• once a potential new drug has been discovered it needs to be developed with preclinical and clinical testing
• pre clinical testing involves drugs being tested on human cells and animals to check for effectiveness and if there are any harmful side effects
• then in the clinical testing phase it is tested in healthy human volunteers to check for side effects, then on those with the illness to find out the optimum dose, then a placebo vs real drug trial is done with a double blind structure.

Question 26

Describe the pre-clinical phase of drug testing.

Answer 26

• drugs are firstly tested human cells and tissues in the lab- this shows if the medicine can get into the cells and have the required effects
• then the drug is tested on animals to see if it works and produces the effect we are looking for this also indicated whether there are harmful side effects, and what the best dose would be.

Question 27

Describe the clinical phase of drug testing.

Answer 27

• if the pre clinical phases have been complete then it can be tested on healthy human volunteers to make sure there are no negative side effects.
• if these results are good the drugs can be tested on people with the illness, this allows the optimum dose to be found, the optimums dose is the dose of drugs which is most effective without side effects
• then patients are placed into 2 groups, one is given a placebo another is given the real drug, this ensures that the drug is actually effective rather than being a placebo effect. This part will also be a double blind trial so the patient won’t know whether they have the the placebo or the real thing but neither does the doctor, this prevent the doctor from being subconsciously influenced and changing their behaviour.

Question 28

What are risk factors that cause non communicable diseases?

Answer 28

• risk factors are things that are linked to increasing the likelihood of a person developing a certain disease, these factors do not guarantee they can get it but rather increase their likelihood
• risk factors can be unavoidable like age or gender but they can also be lifestyle factors like smoking, excessive alcohol consumption and diet

Question 29

How can smoking increase the likelihood of non communicable diseases?

Answer 29

• smoking is associated with cardio vascular disease
• this is because nicotine in the cigarette smoke increases heart rate, increased heart rate causes higher blood pressure
• higher blood pressure can damage artery walls which can contribute to the build of of fatty deposits along the arteries
• this will restrict blood flow and increase the risk of a heart attack or stroke
• smoking can also increase the risk of blood clots forming in arteries and and restricting blood flow leading to heart attacks or strokes

Question 30

How does poor diet cause non communicable diseases?

Answer 30

• poor diets can cause malnutrition with in turn can cause non communicable diseases
• poor diets can also cause obesity which can have an effect on cardiovascular health as excess weight can lead to fatty materials building up in arteries

Question 31

What happens if you lack the nutrient protein?

Answer 31

• a protein deficiency can cause kwashiorkor
• symptoms include an enlarged belly, weak muscles and overall failure to grow properly
• for a more protein rich diet, food like meat and fish should be consumed

Question 32

What happens if you lack the nutrient vitamin c?

Answer 32

• a vitamin c deficiency can cause scurvy
• scurvy can cause muscle and joint pain, swelling and bleeding gums
• if you have scurvy your diet should include vitamin c rich foods

Question 33

What happens if you lack the nutrient vitamin d and calcium?

Answer 33

• a vitamin d and calcium deficiency can cause rickets
• rickets causes soft, curved legs
• to prevent this a diet should include oily fish and dairy products

Question 34

What happens if you lack iron?

Answer 34

• an iron deficiency can cause anaemia
• anaemia can cause tiredness due to there being smaller and less red blood cells
• if you have anaemia your diet should include red meat and leafy greens

Question 35

How does alcohol cause non communicable diseases?

Answer 35

• alcohol can cause liver disease (CIRRHOSIS-scarring of the liver)
• this is because alcohol contains ethanol and whole ethanol can be broken down by the liver, large amounts of it over a long time period of time can cause cirrhosis
• a cirrhotic liver can result in death

Question 36

What are some of the effects of non communicable diseases?

Answer 36

• for example high levels of obesity, smoking or drinking can cause non communicable diseases
• this puts pressure on resources
• it is costly at a national rate as the NHS have to provide the resources
• people who suffer from non communicable diseases also may not be able to work so this affects the economy
• since non communicable diseases can be very common this causes countries to use more resources and money to treat these which can hold back development.

Question 37

How do you calculate BMI?

Answer 37

Weight (kg) / height (m) ^2

Question 38

How do you calculate the waist:hip ratio?

Answer 38

Waist circumference (cm) / hip circumference (cm)

Question 39

What are cardio vascular diseases?

Answer 39

Diseases that are associated with the heart and blood vessels

Question 40

What are arteries and how are they involved with CVD?

Answer 40

• arteries are blood vessels that pump blood away from the heart
• within arteries there can be build ups of cholesterol (fatty deposits’
• fatty deposits can trigger blood clots to form which can block the flow of blood and possible cause a heart attack
• if there is high blood pressure within arteries, the walls can be damaged which is where deposits usually occur

Question 41

What is cholesterol?

Answer 41

• cholesterol is a fatty substance that the body needs to make things like membranes, however too much of this can cause a build up of fatty deposits in arteries that restrict blood flow.

Question 42

What lifestyle changes can you make to treat CVD?

Answer 42

• eating a healthy balanced diet , low is saturated fats (which causes high cholesterol)
• regular exercise
• lose weight if necessary
• stop smoking and drinking
• lifestyle changes are often recommended first as there are no negatives.

Question 43

How can drugs help to treat CVD?

Answer 43

• drugs like statins can reduce the amount of cholesterol in the blood stream, slowing down fatty deposits from being formed, therefore reducing the risk of heart attacks and strokes
• however it can cause liver damage and aching muscles

Question 44

How can surgical procedures treat CVD?

Answer 44

• stents are tubes can be placed inside arteries to keep them open making sure blood is able to flow through
• overtime however stents can irritate the surrounding arteries causing a build up of scar tissue which can again narrow the arteries
• the patient would also have to take drugs to stop blood clotting with could have side effects
• coronary bypass surgery is also another surgery which places a healthy, functioning coronary artery into the blocked section of a blood vessel
• donor hearts can also be used to replace hearts that no longer function, however the new heart may not always start pumping properly and drugs would have to be taken to stop rejection