Disease Flashcards
1
Q
what is a pathogen?
A
a micro organism that causes disease
2
Q
what is a vector?
A
a living factor that transmits the disease
3
Q
what is an epidemic?
A
when a communicable disease spreads rapidly to a lot of people at a local or national level
4
Q
what is a communicable disease?
A
diseases that can be passed from one organism to another, of the same or different species
5
Q
what is a fomite?
A
non-living objects that transmit disease
6
Q
what are some examples of bacterial diseases?
A
- TB
- bacterial meningitis
- ring rot
7
Q
what are the symptoms of TB?
A
- chest pain
- coughing up blood
- back pain
- abdominal pain
- headaches
- weight loss
- ashy skin
8
Q
what is a treatment of TB?
A
antibiotics- long course (9 months)
9
Q
what is the economic impact of TB?
A
1% of the world is infected each year
10
Q
list 4 medical factors that have led to the decline of TB and its severity?
A
- vaccine development
- x-rays
- antibiotics
- better overall health
11
Q
list 3 social factors that have led to the decline of TB and its severity?
A
- better housing
- less overcrowding
- airier and light working conditions
12
Q
why might it be difficult to vaccinate a wild population?
A
you will never be able to find them all or track their offspring
13
Q
what are the symptoms of bacterial meningitis?
A
- irritable
- vomiting
- abnormal reflexes
- hearing loss
- seizures
- fever
- blotchy rash
14
Q
how is bacterial meningitis transmitted?
A
direct contact
15
Q
how is TB transmited?
A
carried in the air- droplet infection, cattle, badgers
16
Q
what are some treatments of bacterial meningitis?
A
antibiotics, vaccination
17
Q
what is the economic impact of bacterial meningitis?
A
10% of people who get it will die
18
Q
what are some symptoms of ringrot?
A
damaged leaves, tubers or stems
19
Q
how is ringrot transmitted?
A
- infected seed tubers
- handling
- direct contact
20
Q
what is the treatment of ringrot?
A
- no cure- leave field empty for 2 years
21
Q
what is the economic impact of ringrot?
A
- lose a lo0t of money from no crops for 2 years
22
Q
what are some examples of viral diseases?
A
- HIV/AIDS
- influenza
- tobacco mosaic virus
23
Q
what are the symptoms of HIV/AIDS?
A
- flu
- TB
24
Q
how is HIV/AIDS transmitted?
A
- direct contact of bodily fluids
- sometimes through placenta
25
what is the treatment of HIV/AIDS?
- retroviral drugs
- no vaccine
26
what is the economic impact of HIV/AIDS?
in 2021, 38.4 mil with HIV and 650,000 died
27
what is the difference between HIV and AIDS?
HIV attacks the immune system and so it allows AIDS to develop
28
what are opportunistic diseases?
disease that infects you if you have a suppressed immune system
29
what are some symptoms of influenza?
- coughing
- sneezing
- fever
- bad digestive system
- headaches
30
how is influenza transmitted?
- vaccinations
- antivirals
31
what is the economic impact of influenza?
- can be fatal
- long periods of time away from work
- in birds or swine flu it can effect farmers
32
what are some symptoms of the tobacco mosaic virus?
- leaves
- flowers and fruits damaged
- stunts growth
- crop loss
33
how is the tobacco mosaic virus transmitted?
- direct contact (leaves toughing)
- indirect (workers-hands/tools)
34
what is the treatment for the tobacco mosaic virus?
- no cure- remove crops, can buy resistant crops
35
what are some economic impacts of the tobacco mosaic virus?
- crop loss- lose money from lack of crops
36
what are some protoctista diseases?
- malaria
- potato/tomato late blight
37
what are some symptoms of malaria?
- anaemic
- tired
- pain
- headaches
- chills
- vomitting
38
how is malaria transmitted?
mosquitoes
39
what are some treatments of malaria?
- can't get rid of it
- antimalaria drugs
- insect repellent
- insect net
40
what are some economic impacts of malaria?
in 2012, 627,000 deaths
41
what are some symptoms of potato/tomato late blight?
- hyphae- tiny threads of disease- penetrates leaves, tubers and fruits
42
what is the transmission of potato/tomato late blight?
spores spread by the wind
43
what are the treatments of potato/tomato late blight?
- no treatment- chemicals to prevent
44
what is the economic impact of potato/tomato late blight?
millions of pounds of damage each year
45
what are some fungal diseases?
- black sigatoka
- ring worm
- athletes foot
46
what are some symptoms of black sigatoka?
hyphae growing through leaves and fruit turn black
47
how is black sigatoka transmitted?
water and wind born spores
48
what is the treatment for black sigatoka?
no cure- chemical preventatives
49
what is the economic impact of black sigatoka?
50% reduction in yield
50
what are the symptoms of ringworm?
- in cattle- grey circular areas of dry skin
- humans- red, itchy circles
51
how is ringworm transmitted?
- direct contact
- fomites
52
what is the treatment of ring worm?
anti fungal cream
53
what are the symptoms of athletes foot?
cracking, scaling, itching or sore skin
54
how is athletes foot transmitted?
- fomites
- direct contact
55
what is the treatment for athletes foot?
anti fungal cream
56
what are monoclonal antibodies?
an antibody produced from a cell lineage made by cloning a unique WBC
57
how do clonal antibodies work?
they work by triggering the immune system and helping it to attack cancer
58
how do they detect plant diseases?
if the pathogens antigens are present in the plant tissue when the monoclonal antibody sticks to it
59
what are the types of pathogen?
- bacteria
- fungi
- viruses
- protoctista
60
what do pathogens have to do to cause disease?
- travel from host to host
- get into tissues
- reproduce
- cause damage
61
what are the different shapes of bacteria?
- cocci
- spirillum
- virbio
- bacilli
62
why can the shape cocci live in drier environments?
it has less surface area per volume than others
63
what shape is the shape spirillum?
spiral cells
64
how does spirillum meet less resistance in surrounding water?
it move with a corkscrew motion
65
why is it important that bacilli and vibrio have a greater surface area to volume ration?
it means they can take up nutrients from dilute solutions more effectively
66
what colour does gram negative bacteria appear under a light microscope, what stain is used and give an example?
- red
- stained with safranin
- E.Coli
67
what colour does gram positive bacteria appear under a light microscope, what stain is used and give an example?
- purple/blue
- crystal violet
- MRSA
68
how often can bacteria divide?
one bacteria can divide into 2 new ones every 20 minutes
69
how do bacteria cause disease?
they produce toxins and cause symptoms by cell damage. they damage ell membranes, enzymes or genetic material
70
what is the structure of viruses?
- some genetic material is surrounded by a protein shell
- they are non-living as they cannot replicate by themselves
71
what is a bacteriophage?
a virus that infects bacterial cells
72
what is the process of viral reproduction?
1) virus attaches to a specific host cell
2) genetic material from virus is injected into the host cell
3) the viral genes cause the host cell to make new viruses
4) the host cell splits open, releasing the new virus
73
protists are p______?
parasitic
74
what do many protoctists need to transfer them to their host?
a vector
75
what is disease?
any disorder or malfunction of the mind or body that leads away from good health
76
what is health?
the complete state of social, emotional or physical wellbeing, not just the absence of disease
77
what do you need to be in good health?
in good mental or physical health
78
what is an infectious disease?
disease that can be transmitted between organisms
79
label of bacterial cell on IRL flashy
80
label of fungal cell of IRL flashy
81
what does bacteria cause?
cause disease by damaging cells or replacing toxic waste products
82
where do some fungi live and what do they send out?
some live in the skin and send out hyphae to the surface
83
what do viruses do?
invade cells and take over the genetic machinery, the cells then replicate the virus until it bursts
84
what are protoctista?
organisms that cause harm by entering the cells and feeding on the contents
85
what is inoculation?
pathogens entering through a break in the skin (sex), animal bites (rabies) or sharing needles
86
how does ingestion cause disease?
taking in contaminated food or drink or transferring pathogens from the hands to the mouth
87
what are some ways disease can be transmitted through indirect contact?
- water
- vectors
- droplet infection
- fomites
88
how do fomites transmit disease?
inanimate objects such as bedding, socks and cosmetics transfer pathogens
89
how do droplet infections work?
droplets of saliva or mucus are expelled from your mouth as you cough or sneeze. healthy individuals can then breathe these in
90
how to vectors transmit disease?
transmit communicable pathogens from one host to another, often animals
91
how can water transmit disease?
can also be a vector
92
what are the three key factors to reduce the spread of disease in humans?
- hand washing
- improvements in living and working conditions- reduce overcrowding and ensure good nutrition
- disposal of bodily and household waste effectively
93
what are some factors affecting transmission in animals?
- overcrowded living and working conditions
- poor nutrition
- poor disposal of waste
- climate change
94
what are some examples of transmission between animals?
bird flu and brucellosis
95
how can transmission between animals be minimised?
- reducing close contact with animals
- washing hands thoroughly
96
what is direct transmission?
when the pathogen is directly transferred from one individual to another
97
what is indirect transmission?
when pathogens travel from one individual to another indirectly
98
why is it important to understand how pathogens are transmitted?
to work out ways to reduce and prevent transmission- strategic planning
99
what are the key factors to reduce the spread of disease in plants?
- leave room between plants
- clear fields as thoroughly as possible after harvesting
- rotate crops
- strict hygiene practices
- control insect vectors
100
what are factors that affect transmission in plants?
- planting a variety of crops that are susceptible
- overcrowding increases touching
- poor mineral transmission
- damp and warm conditions
101
what are some primary defences in a plant?
- cellulose cell wall
- waxy cuticle
- bark
102
what do plants do instead of healing diseased tissue?
they seal it off and sacrifice it
103
where do plants grow from and why?
from the meristem so they can replace damage
104
what are the different types of meristem?
- apical
- lateral
105
what does an apical meristem do?
causes primary growth
106
where is the apical meristem found?
tips of shoots and roots
107
what does the lateral meristem do?
causes secondary growth
108
where is the lateral meristem found?
at the cambium
109
how do plants recognise an attack?
- receptors respond to molecules from pathogens or chemicals released that attack the cell wall
- the cells will then release signalling molecules
110
what do signalling molecules do in the plant when an attack is recognised?
they switch on genes in the nucleus which triggers cellular responses such as producing chemicals, sending alarm signals and strengthening the cell wall
111
what do polysaccharides do in response to an attack in a plant?
increase synthesis of callose and lignin
112
where is callose deposited and what does it do in an attack of the plant?
in the plasmodesmata between the cell wall and membrane in cells next to the infected cells, making it harder for the invading pathogen to spread
113
what does lignin do in an attack of a plant?
makes the mechanical barrier even stronger
114
what does callose do in an attack of the plant?
blocks the sieve plates of the phloem, sealing off infection and preventing spread
115
why do plants produce chemicals?
to either repel insect vectors or to kill invading pathogens
116
why are some chemicals extracted from plants?
for insecticides, fungicides etc
117
what linkages does callose have?
beta 1-3 and beta 1-6 linkages between the glucose monomers that are important in the plant response to infection
118
is callose made up of alpha or beta glucose?
beta
119
what is the purpose of callose being initially synthesised and deposited between the cell wall and cell membrane next to infected cells?
the callose papillae act as a barrier, preventing the pathogens entering the plant cells around the site of infection
120
what is a retrovirus?
a virus that contains RNA and not DNA
121
what is an antigen?
an identifying chemical on the surface of a cell hat triggers an immune response
122
what are antibodies?
y shaped glycoproteins made by B-cells of the immune system in response to the presence of an antigen
123
what is an immune response?
a biological response that protects the body by recognising and responding to antigens and by destroying substances carrying non-self antigens
124
what is the definition of immune?
totally or partially resistant to a particular infectious disease or pathogen
125
what are the two types of WBC's?
- lymphocyte
- phagocyte
126
what are the types of lymphocyte?
- B lymphocyte
- T lymphocyte
127
what are the type of B lymphocytes?
- plasma cells
- B memory cells
- B effector
128
what are the types of T lymphocytes?
- T helper cells (most helpful)
- T memory cells
- T killer cells
- T regulatory cells
129
what are the types of phagocytes?
- neutrophils
- macrophages
130
what are neutrophils?
- smaller
- 60% of all WBC's
- short lived
- multi lobed nucleus
- attracted to histamines
131
what are macrophages?
- larger
- involved in antigen presentation
- more complex and slower process
- round nucleus
- cut up pathogen to produce antigen presenting cell
132
what is phagocytosis?
the ingestion of bacteria and other material by phagocytes
133
what is primary defences?
barriers to prevent pathogens entering- non specific
134
what are some examples of primary defences?
- expulsive reflexes- coughing, sneezing, diarrhoea
- nasal cavity- hairs and mucus
- stomach- acid
- ear- cerumen inhibits bacteria
- skin- impervious barrier
- eyes- cleansed by tears which contain chemicals
135
what are the primary repsonses?
- blood clotting
- inflammatory response
- fever
- phagocytes
- neutrophil phagocytosis
- macrophage phagocytosis
- cytokines
- opsonin
136
what is the process of blood clotting?
- platelets come into contact with collagen in the skin or walls of the damaged blood vessels and adhere to it
- they secrete two important substances:
- thromboplastin- enzyme that catalyses the cascade of reactions
- serotonin- causes blood vessels to contract reducing blood supply to the area
137
what does inflammation cause?
heat, pain, redness and swelling of the tissue (localised)
138
what is the process of inflammatory response?
- mast cells (a type of WBC) are activated in response to pathogens/allergens/irritants
- once activated they release the chemicals histamine and cytokines
139
where are mast cells found?
found in mucosal surfaces on the gut and lung, in the skin and around blood vessels
140
what do histamines do?
- cause blood vessels to dilate and become more permeable causing localised heat and redness
- blood vessel walls become more permeable so more blood plasma is forced out which causes swelling (odema) and pain
141
what do cytokines do?
attract WBC's (phagocytes) to the site which dispose of pathogens and phagocytosis
142
what happens when you have a fever?
- normal body temperature is maintained by the hypothalamus in the brain (processing centre of homeostasis)
- pathogens reproduce optimally at or below this temp
- pathogens trigger cytokines to signal your hypothalamus to increase your body temp
- this inhibits pathogen reproduction
143
what are phagocytes?
specialised WBC's that build up at the site of infection and engulf and destroy pathogens
144
what is the process of neutrophil phagocytosis?
1) pathogen is tagged with opsonin
2) it is engulfed into a phagosome
3) lysosomes contain hydrolytic enzymes
4) phagosome fuses with lysosome to make a phagolysosome
5) pathogen is then digested partially
6) phagolysosome fuses with cell membrane
7) pathogen is expelled with exocytosis
145
what is the process of macrophage phagocytosis?
1) pathogen is tagged with opsonin
2) it is engulfed into a phagosome
3) lysosomes contain hydrolytic enzymes
4) phagosome fuses with lysosome to make a phagolysosome
5) pathogen is then digested partially
6) the antigens are combined with glycoproteins to make major histocompatibility complex (MHC)
7) the antigen MHC is presented on the cell surface by antigen presenting cells (APC)
146
what are cytokines?
cell signalling molecules
147
what do cytokines do?
inform other phagocytes when there is a pathogen present
148
what can cytokines do?
- increase body temp
- stimulate the specific immune response
149
what do opsonins do?
bind to pathogens and tag them so they can be easily recognised by phagocytes
150
what are lymphocytes?
specialised WBC's that are involved in the specific immune response
151
where do lymphocytes originate from?
- bone marrow
- specialised cells are derived from haematopoietic stem cells
- T cells mature in the thymus gland
152
what is clonal selection?
the theory that exposure to a specific antigen selectively stimulates the proliferation of the cell with the appropriate antibody
153
what is clonal expansion?
used whenever the cells are replicating by mitosis
154
what is cell mediated immunity?
the immune response mediated by activating T helper cells
155
what can mediated immunity lead to?
the other B and T cells being activated and propagated
156
what are interkleukins?
the name given to cytokines made in cell mediated immunity
157
what do T helper cells do?
- trigger the specific immune response by producing interleukins
- bind to the specific antigen on the surface of an APC (macrophage)
158
what do T helper cells have on their cell membrane?
CD4 receptors
159
what is the causal agent agent for malaria?
Plasmodium
160
what is the causal agent for athletes foot?
Trichophyton
161
what do B memory cells do?
- immunological memory
- 2nd infection of that pathogen
- differentiation to specific B cells
162
what do B effector cells do?
differentiate into B effector and plasma cells
163
what do plasma cells do?
produce specific antibodies to the antigen
164
what do T memory cells do?
- immunological memory
- produce T cells
165
what do T killer cells do?
- produce a chemical called perphorin to make a hole in the cell membrane
- they inject it with H2O2
166
what do T regulator cells do?
- regulate the immune system by suppression once the pathogen has gone
- recognises self pathogens
- prevents autoimmune response
167
what is the humoral response?
- B cells are associated with the humoral response
- they are activated by the T cells
- this is the response associated with circulating antibodies
168
what will the antibodies do in the humoral response?
they will bind to any foreign antigen they find, this could be on a pathogen or on a body cell that has become an antigen presenting cell
169
what are the main cells involved in humoral immunity?
B cells
170
what are the main cells involved in cell mediated immunity ?
T helper
171
where do T helper cells develop?
thymus
172
are antibodies involved in humoral immunity?
yes
173
are antibodies involved in cell mediated immunity?
no
174
how are pathogens identified in humoral immunity?
they have antibodies specific to antigens
175
how are pathogens identified in cell mediated immunity?
they are presented on macrophage APC
176
how are pathogens killed in humoral immunity?
either engulfed to become B cell APC's or antibodies disable them
177
how are pathogens killed in cell mediated immunity?
T helper cells trigger T killer cells, plasma cells and macrophages
178
how do cells divide once they are stimulated in humoral immunity?
clonal expansion
179
how do cells divide once they are stimulated in cell mediated immunity?
mitosis
179
how are antibodies produced?
by plasma cells
179
what is the role of antibodies?
1) phagocytosis
- antibody of the antigen/antibody complex
- acts as opsonin
- attracts phagocytes so it is engulfed
2) neutralisation stops pathogens from entering host cells
3) agglutination of microbes causes pathogens to clump together prevents replication therefor prevents spread
4) - antibodies can act as anti-toxins
- binds to the toxin and makes it harmless
179
what is an autoimmune disease?
a condition or illness that results from an autoimmune response
180
when does an autoimmune response occur?
when the immune system acts against its own cells and destroys healthy tissues in the body
180
why are immunosuppression drugs not a good treatment?
it could also supress the normal immune system
180
how do autoimmune diseases occur?
it is not fully understood but tends to be genetic
180
what is the cure for Rheumatoid arthritis?
no cure- only can treat it with anti-inflammatory drugs, steroids, pain relief or immunosuppression
180
what is Rheumatoid arthritis?
a chronic progressive disease, causing inflammation in the joints and resulting in painful deformity and immobility, especially in the fingers, wrists, feet and ankles
181
What does lupus effect?
Skin, joints and any organ
181
what is Lupus?
a complex and poorly misunderstood condition that effects many parts of the body, ranging from mild to life threatening
182
What is the cure for lupus?
No cure
182
See IRL flashy for antibody structure
183
Why do we need new medicines?
- pathogens become resistant to existing drugs
- new diseases emerge
- new vaccines needed e.g. for HIV
- existing vaccines can be improved
184
Who discovered the first medicine?
Alexander Fleming- penicillin
184
What are the sources of medicines?
Obtained from or made from natural resources found in plants, animals, microorganisms and fungi
184
What is pharmacogenetics?
Using information from the genome to personalise medicine that will work for the individuals genetics and disease
184
What is synthetic biology?
Creating genetically modified organisms hat produce drugs
184
What is nanotechnology?
Nano particles used to deliver drugs to sites within cells
185
Why must biodiversity be maintained in re,action to medicines?
Biodiversity is a source of many potential medicines as different organisms produce unique chemicals that can be used to develop new drugs
186
Give examples of living organisms form which drugs have already been extracted?
- penicillium mold - penicillin
- poppy plant - morphine
- willow bark - aspirin
186
Explain how our ancestors may have discovered that poppy seeds contain a chemical that has anaesthetic properties?
- early humans likely experimented with different plants and observed their effects on pain and consciousness
- may have noticed that consuming or applying poppy extracts reduced pain/caused drowsiness
186
What long term measures can be used to reduce antibiotic resistance occurring?
- restricting unnecessary antibiotic prescriptions
- developing new antibiotics
186
Where is antibiotic resistance a particular problem and why?
- hospitals
- care homes
- antibiotics are frequently used to help people
186
What are thought to be the 2 main causes of increased rates of antibiotic resistance?
- overuse of antibiotics
- horizontal gene transfer between bacteria
186
Where is MRSA found?
Skin or nose
186
What does MRSA cause?
Boils, abscesses, fatal septicaemia
187
When do problems start with MRSA?
- when it enters the blood stream through wounds
- becomes difficult to treat due to resistance
187
How do antibiotics damage bacteria?
- they inhibit cell wall synthesis e.g penicillin prevents peptidoglycan production
- disrupting protein synthesis
- blocking metabolic pathways
187
Where is C.difficile found?
Human gut
187
What does C.difficile cause?
Diarrhoea, colitis, toxin production
187
When do problems with C.difficile start?
- broad specimen antibiotics kill beneficial gut bacteria
- produces toxins that damage the intestinal lining
- spreads in hospitals
211
What are vaccines?
A way of artificially activating the immune system to produce antibodies
212
What do vaccines contain?
- live attenuated (weakened) microorganisms
- killed or inactive bacteria or viruses
- harmless toxins
- antigens extracted from pathogens
- genetically engineered antigen
- genetically engineered RNA
- viral vector
213
What are some approaches to vaccinating people and how do they help prevent the spread of disease?
- heard vaccination- vaccinate most/all people
- stops infection spreading within population
- ring vaccination- vaccinate all people around victim
- contains spread within ring- stops transmission
214
What are the types of immunity you can have to a disease?
- artificial immunity
- natural immunity
215
What is artificial immunity?
A vaccine which injects artificially weakened, killed or inactivated pathogens into the body to allow an immune response
216
When might a vaccine be given to fight a disease immediately and is it short or long term?
- If an infection or fatal disease has occurred
- short term
217
What is short term immunity?
Pathogen is encountered naturally which gives natural activation of the immune system involving T cells,is and B cells
OR
Antibodies are received through the mothers milk or placenta
218
What is natural active immunity?
- when you come into contact with a pathogen for the first time
- takes time for an immune response
- symptoms develop
- antibodies and memory cells are produced
219
What is artificial active immunity?
- vaccination with killed/inactivated/artificially weakened version of the pathogen
- immune system stimulated to produce its own antibodies and memory cells
- antigen is intact but no rise of infection
220
What is natural passive immunity?
- lasts until immune system of a baby begins to make its own antibodies
- e.g colostrum
221
What is artificial passive immunity?
- provides temporary immunity
- can be life saving
- antibodies against a fatal disease are formed in an animal, extracted and injected into the blood stream of another
222
What is personalised medicine?
A medical approach that tailors treatments to an individuals genetic makeup, ensuring medications are more effective
223
What is pharmacogenomics?
The study of how genes affect an individuals response to drugs
224
How has treatment for breast cancer improved as a result of pharmacogenetics?
- it enabled target therapies
- e.g. Herceptin is a drug specifically effective in patients with HER2 positive breast cancer, a condition identified through genetic testing
- this increases the treatment success rate and reduces unnecessary side effects
225
What is synthetic biology?
An interdisciplinary field that involves designing and engineering new biological parts, systems and organisms
226
How can mammals be used to produce therapeutic proteins?
Can be engineered to produce it in their milk
227
How can nanotechnology be used in cells?
To deliver drugs more precisely, improve imaging techniques, and repair damaged tissues at the molecular level
228
Why have antibiotics become so widely used?
They effectively treat bacteria infections, reducing illnesses and mortality
229
Why do populations of antibiotic-resistant bacteria grow large very quickly?
Because natural selection favours bacteria with resistance genes
230
In which countries are antibiotics routinely given to animal feed?
USA, China and Brazil
231
Why is putting antibiotics in animal feed illegal in the UK?
It contributes to antibiotic resistance, which can spread to humans in the food chain
232
Name two species of bacteria that show antibiotic resistance?
- MRSA
- C.difficile
