Topic 5- Health And Disease Flashcards
1
Q
Define health
A
A state of complete physical, metal and social well being
2
Q
Define disease
A
A disorder of the body or mind that negatively affects an individuals health
3
Q
What are two types of disease?
A
Communicable
Non communicable
4
Q
What is a communicable disease?
A
A disease that is passed directly between individuals
Caused by a pathogen
5
Q
Define pathogen
A
A disease causing organism e.g virus, fungi, bacteria, protists
6
Q
What is a non communicable disease?
A
A disease that cannot be transmitted between Individuals
Generally long lasting with a slow onset
Caused by lifestyle, environmental conditions, genetic mutations
7
Q
What is a symptom?
A
A change experienced by an organism that indicates disease
8
Q
Why does having an illness make an individual more likely to contract another disease?
A
A disease may weaken an individual’s immune system making the increasing,y susceptible to other infections
9
Q
Describe cholera
A
Caused by Vibrio cholerae bacterium
Speed by drinking water or washing in water that has been contaminated with infectious faeces
Symptoms. Diarrhoea , vomiting
10
Q
How can the incidence of cholera be reduced?
A
Access to clean water
Improved sanitation ( sewage disposal )
11
Q
Describe TB
A
Caused by bacterium
It is airborne bacteria spread by droplets
Symptoms = lung damage, chesty cough, wheezing
12
Q
How can the transmission of TB be reduced?
A
Improved hygiene
Infected individuals should avoid crowded areas
Increased ventilation
13
Q
Describe chalara ash dieback
A
Cause by a fungus that infects ash trees
Spread via airborne spores which are carried by wind
Causes dark legions on bark and blackened leaves which die
14
Q
How can the transmission of chalara ash dieback be reduced ?
A
Control the movement of ash trees
Kill infected plants
Replant with a different species
15
Q
Describe malaria
A
Caused by protists
Spread by mosquito vectors . Pick up when feeding on infected organism and transmit to other organisms when feeding
Flu like symptoms , damage to red blood cells , liver damage
16
Q
How can the incidence of malaria be reduced?
A
Mosquito nets
Insect repellant
Cover arms and e,bs
17
Q
Describe stomach ulcers
A
Caused by bacterium
Transmitted orally by eating infected foods or drinking infected water
Symptoms = stomach spin, vomiting nausea
18
Q
How can the transmission of the bacteria that causes stomach ulcers be reduced?
A
Access to clean water
Improve hygiene
Improved sanitation
19
Q
Describe Ebola
A
Caused by Ebola virus
Spread by direct contact with infected body fluids
Symptoms = fever, diarrhoea, vomiting, internal bleeding
20
Q
How can the transmission of Ebola be reduced?
A
Improve hygiene
Isolating infected individuals
Sterilisation of outbreak areas
21
Q
Describe simply how viruses causes disease?
A
They enter just cells and replicate inside of them. The host cells rupture, releasing new viruses
22
Q
How do viruses differ from other microorganisms?
A
Viruses are not living organisms. They do not reproduce and can only replicate inside a host cell
23
Q
By what two pathways do viruses replicate inside living cells ?
A
Lytic pathway
Lysogenic pathway
24
Q
Describe the lytic pathway
A
- Virus binds to specific receptors on host cells
- Virus injects it’s DNA into host cell and replicates it’s DNA using host cell machinery
- New viral structures are produced and assembled
- Host cell ruptures, re,asking new viruses
25
Describe the lysogenic pathway .
1. Virus binds to specific receptors on host cell
2. Viral DNA injected into host cell becomes interstates into host cell genome
3. Viral DNA replicates each time the host cell divides. However the cell remains normal.
4. Trigger chases the activation of viral DNA. It enters the lytic pathway
26
Describe HIV
Caused by human immunodeficiency virus
Spread by direct contact with infected body fluids
Destroys white blood cells making the individual immunodeficient and increasing,y susceptible to other diseases
27
How can the spread of HIV be reduced?
Use of condoms and protected sex
No needled exchange
Screening blood for HIV
Deterring infected mothers from breast feeding
28
Describing chlamydia
Caused by bacterium
Spread through sexual contact or direct contact with genita, d,uids
Can result in infertility
29
How can the transmission of chlamydia be reduced
Used of condoms and protected sex
Screening
30
Describe the physical defence system within plants
Waterproof waxy cuticle - surface barrier preventing the entry of pathogens
Cellulose cell wall- further barrier against pathogens
31
Give some examples of chemical barriers in plants
Secretion of toxins to reduce damage by pests
Production of antibacterial chemicals that kill bacterial pathogens
32
Why are chemicals produced by plants useful?
They produce physiological effects on the body so can be used in medicines to treat disease
33
Give an example of a medicine derived from plants
Aspirin - painkiller - bark leaves of Salix alba
34
Why are plant defence systems important?
Plants are producers so all organisms higher up in food chains rely upon their survival and ability to fight disease
Important in maintains human food security
35
How can plant diseases be detected and identified in the field ?
Observation of symptoms
Analysis of the distribution of affected plants can indicate the type of pathogen involved
Changing environmental conditions to eliminate other causes such as nutrient deficiencies
36
Why is it difficult to identify a disease using symptoms alone?
Many disease may have similar symptoms
37
How can plant diseases be detected and identified in the lab
Detection of foreign antigens in a sample of plant tissue using monoclonal antibodies
Analysis kf DNA to identify any pathogen DNA in a tissue sample
38
What is a non specific defence
Always present
Same for all organisms
Prevent pathogens from entering the body
39
Give some examples of the body’s physical defence system,
Skins - protective surface barrier
Blood clotting - platelets seal wounds preventing entry of pathogens into the blood
Respiratory tract- muscles traps pathogens, cilia waft mucus to the back of the throat where it is swallowed
40
Give some examples of the body’s chemical defence system
Tears contain lysozyme which digests bacterial cell walls killing bacteria and protecting the eye
Hydrochloride acid in stomach - acidic pH kills pathogens that are swallowed
41
What is the immune system
The body’s defence against pathogens once they have entered the body
Aims to prevent or minimise disease caused by pathogens
42
How do white blood cells detect pathogens in the body
Pathogens have unique antigens in their surface which are detected by specialised receptors on white blood cells
43
How does the immune system destroy pathogens ?
B lymphocytes produces antibodies in response to a particular antigen
Each antibody is specific to an antigen and binds to it
Antibodies tag pathogens or clump them together, disabling them so that they can be killed by other white blood cells
44
What are memory lymphocytes?
White blood cells produced in response to a foreign antigen that remain in the body after a pathogen has been destroyed
Provide immunity - if the body is re infected, antibodies are produced more rapidly and the pathogen is destroyed before it can produce disease symptoms
45
Compare the primary and secondary immune responses
The secondary response produces antibodies more rapidly and in higher concentrations than in the primary response. The pathogen is destroyed before it can cause symptoms
46
What is a vaccination
Deliberate exposure of an individual to foreign antigens
Triggers an immune response ( produces antibodies ) and provides immunity ( due to memory cells)
The individual does not contract the disease that they are being immunised against
47
Describe the components of a vaccine!
Dead, weakened or inactivated pathogens with their surface antigens still present
48
What are the benefits of vaccinations
Herd immunity = vaccination of a significant proportion of the population gives some protection to individuals who are not immune
Helps to prevent epidemic and pandemics
49
What’s the drawbacks of vaccinations?
High mutation rate of viruses changes the structure of viral antigens making vaccines that are already available ineffective
Not guaranteed to work
Inactivated pathogens may mutate and become pathogenic
May cause an adverse reaction
Vaccination programmes are costly
50
Give some examples of non communicable diseases
Cancer
Diabetes
Cardiovascular diseases
Chronic respiratory diseases e.f asthma
51
What is a risk factor?
A variable associated with a greater chance of developing a disease or infection
52
Outline the factors that can affect the risk of developing a non communicable disease
Lifestyle factors e.g diet, exercise, alcohol, smoking
Environmental factors e.g exposure to pollution
Genetics e.g alleles that increase the risk of cancer
53
Correlation does not mean causation .. explain this
Correlation between a risk factor and a disease does not mean that the risk factor causes the disease. Other factors may be involved and some may be linked
54
Describe how exercise affects the risk of some non communicable diseases
Regular exercise decreases fat stores, reducing obesity
It decreases heart rate, recovery time and blood pressure lowering the risk of CVD
55
Describe how diet affects the risk of some non communicable diseases
Diet high in saturated fat raises blood cholesterol levels , increasing the deposition in the arteries - greater risk of CVD
Obesity and the consumption of large amounts of simple sugars increases the risk of type 2 diabetes
Malnourishment increases the risk of deficiency diseases
56
Give an example of a deficiency disease
Scurvy ( vitamin C deficiency)
Anemia ( iron deficiency)
57
What is BMI?
A value based on height and mass used to categorise an individual as underweight, normal weigh, overweight or obese
58
How is BMI calculated
BMI = mass/ height ^2
59
Why isn’t BMI always an accurate measure of obesity
Fat and muscle tissue cannot be distinguished so athletes may be incorrectly categorised as obese
60
How is an individual’s waist-to-hip ratio calculated?
Waist-to-hip ratio = waist circumference/ hip circumference
61
Describe how alcohol affects the risk of some non communicable diseases
Alcohol broken down into toxic products in the liver which build up and cause cirrhosis
Alcohol raises blood pressure thus increasing the risk of CVD
Toxic products in alcohol can cause mutations to DNA increasing the risk of cancer
62
Describe how smoking affects the risk of some non communicable diseases
Nicotine raises heart rate increasing the risk of CVD
Carbon monoxide lowers ability of red blood cells to carry oxygen, heart rate increases increasing risk of CVD
Carcinogens in tar can cause mutations to DNA increasing the risk of cancer
Smoking increases the risk of lung diseases
63
How do environmental factors affect the risk of some non communicable diseases
Long term exposure to pollution damages the airways increasing the risk of lung diseases and lung cancer
Exposure to UV radiation damages DNA increasing the risk of DNA mutations and skin cancer
64
How do genetics affect the risk of some non communicable diseases
The risks of some diseases such a type 2 diabetes , lung cancer and CVD and increased if a family member has had these conditions
Faulty genes can be inherited which increase the risk of conditions such as breast cancer
65
How do diseases interact with each other
Some diseases may cause other infections to develop e.g HIV weakens the immune system , making an individual more susceptible to other infections such as TB
Some diseases reduce the risk of contracting other infections
66
Describe the effects of non communicable disease on a local national and global level
Increased incidence of non communicable disease puts a strain on local hospitals which have limited resources
Increased pressure on NHS to provide treatment to a larger number of patients. Sickness related absence impacts a country’s economy
High prevalence of malnutrition in LEDCs slows the development of such countries which in turn impacts global development
67
What is cardiovascular disease
Group of diseases affecting the heart or blood vessels
Build up of fatty deposits on the walls of the arteries forms a theory as which reduce blood flow to muscle tissue
Blood clots may form, blocking the arteries and stopping blood flow completely. This can lead to a heart attack or stroke
68
How can CVD lead to a heart attack
Obstruction of a coronary artery due to an atheroma or blood clot
Results in loss blood supply to an area of heart muscle
This causes death of the cells and leads to a heart attack
69
How can CVD be treated
Improving diet and lifestyle
Medication
Surgery
70
What changes to diet and lifestyle can be made to reduce the risk of CVD
Regular exercise
Reduce intake of saturated fat
Maintenance of a healthy weight
Diet low in salt
Reduce stress
Stop smoking and drinking
71
How effective are changes to lifestyle and diet in treating CVD
Although not themselves effective , they can enhance efficiency of other methods of treatment
72
What are stents ?
Small hollow tubes inserted into the lumen of arteries to keep them open
Require surgery to insert
73
What are the problems with the use of stents to treat CVD
Stents cause the growth of scar tissue in the arteries over time further narrowing the lumen
Blood clots may stick to stents
74
What is a coronary bypass
Using a blood vessel from another region of the body to divert blood around a blockage in the coronary artery
75
What does a heart transplant involve?
Replacing a damaged heart with a donated heart
Immunosuppressant drugs taken to prevent organ rejection
76
Describe the benefits of heart surgery
Lifesaving
Can provide a permanent solution to a disease
77
Describe the risk of heart surgery
Involves many risks like infection and excessive bleeding
Difficult to find a suitable doctors
Risk of rejection
Immunosuppressant drugs must be taken for life
Long recovery time
Expensive
78
What is an antibiotic
A substance that kills or inhibits the growth of bacteria
No effect on cells in the host organism
Produced by living organisms
79
Describe how target molecules for new medicines can be identified
Comparisons of the genomes of unaffected individuals and those who are affected by a disease to identify potential disease causing alleles
The allies themselves or the proteins that they code for can be used as a target
80
Outline the stages of drug developments
Screening for potential drugs
Preclinical trials
Clinical trials
Approved by a medical agency
81
Describe the process of screening
Uses a machine to test large libraries of chemical substances
Enables indemnification of pre existing chemicals which may affect the target molecule
Vhemcia,s may be a,there’d allowing scientists to produce a drug that reacts with target molecules in a specific way
82
What do preclinical trials involve?
Drug tested on cultured human cells and using computer models to determine its toxicity and efficiency
Drug then tested on live animals to establish a safe dose for humans and observe any side effects
83
What happens during clinical testing?
The drug first tested on healthy human volunteers to ensure that it is safe to use and has no other unwanted effects on the body
Drug then tested on patients with the the disease to determine its efficacy. Dosage is slowly increased until an upper limit is established. Optimum dosage is found
84
What are placebos ?
A substance that appears just like the real drug but has no effect on the recipient
85
What is a blind trial?
Where the participants don’t know whether they are receiving the new drug or the placebo
Prevents the patients bias affecting the results
86
What is a double blind trial
Neither the participants nor the doctors know who is receiving the new drug or the placebo
Prevents bias from doctors when Alan lysine the results
87
What is the problem associated with using placebos on patients with a disease?
Is it ethical to prescribe a sick patient with a placebo knowing that it will not help their condition improve
88
What are monoclonal antibodies?
Antibodies that are clones from one parent cell
Specific to one type of antigen
89
How are monoclonal antibodies produced?
1. Specific antigen injected into an animal
2. B lymphocytes producing complementary antibodies extracted.
3. B lymphocytes fuse with myeloma cells to form hybridoma cells
4. Hybridoma cells cultures
5. Monolclona, antibodies collected and purified
90
What are myeloma cells?
Type of tumour cell?
