Communicable Diseases, Prevention And The Immune System Flashcards
(175 cards)
1
Q
Define health
A
State of mental, physical and social wellbeing
2
Q
Define disease
A
Departure from health due to malfunction of mind or body that cause symptoms
3
Q
What is a pathogen
A
An infective organism which causes disease
4
Q
What are the four types of pathogen
A
Bacteria
Fungi
Viruses
Protoctista
5
Q
What do vectors do
A
Carry pathogens from one organism to another
6
Q
Define degenerative disease
A
Results in gradual decline in bodily functions
7
Q
Define infectious disease
A
Diseases which are transmitted by a pathogenic organism which invades the body
8
Q
What does self inflicted disease mean
A
Disease caused by poor choices
9
Q
Define deficiency disease
A
Diseases caused by poor diet
10
Q
Define inherited disease
A
Disease caused by genetic faults passed on from parents
11
Q
Define mental disease
A
Diseases affecting the mind
12
Q
Define physical disease
A
Permanent or temporary damage to part of the body
13
Q
What is a parasite
A
Organism that lives in or on a host taking nutrition and causes harm
14
Q
What does a parasite take from the host
A
- nutrition
- warmth
- protection
15
Q
How does bacteria affect the host
A
Damaging cells
Producing toxins
16
Q
How fast does a bacteria do asexual reproduction
What is the process called
A
Every 20 minutes
Called binary fission
17
Q
Bacteria is a prokaryote, what is the cell structure like
A
No nucleus
No membrane bound organelles
18
Q
What are the two ways of classifying bacteria
A
By the shape ( rod shape, spherical, spiral…)
By the cell walls
19
Q
How can you identify bacteria by the cell walls
A
Gram staining- identify the thickness of the peptidoglycan cell walls
This shows whether they are gram positive or gram negative
20
Q
What do viruses make people ill
A
Invading cells Take over genetic machinery Make copies of viruses using cells ribosomes etc Host cell bursts Copies are released 🔁
21
Q
What does a fungi do to make people ill
A
Live on the skin
Send out reproductive hyphae
These produce spores
And cause redness and irritation
They digest living cells and then destroy them
22
Q
What type of organism are fungi
A
Eukaryotic
23
Q
What is a saprophyte
A
Digest dead/decaying matter
24
Q
How do fungi spread
A
They produce spores which reproduce
These can travel large distances ( ie in the wind )
25
What type of organism is protoctista
Single called Eukaryote
26
How do protoctista damage the host tissue directly
They digest and use the contents of a cell when they reproduce and eventually break open cells
27
What do toxins do
Break down the plasma membranes
Damage and inactivate enzymes
Prevent cell division
28
Name the three ways of direct transmission in animals
1) direct contact
2) inoculation (break into the skin)
3) ingestion
29
Name the three ways of indirect transmission in animals
1) formites ( bedding/ socks)
2) droplet infection
3) vectors
30
How can the probability of a catching a communicable disease
- overcrowded living places
- compromised immune system ( immunosuppressant drugs)
- poor disposal of waste
31
How are diseases directly transmitted in plants
-direct contact
32
How are plant diseases indirectly transmitted
- soil contamination
| - vectors ( wind water animals)
33
What are some of the factors that affect the transmission of disease in plants
- over- crowding
- poor mineral nutrition
- damp, war conditions ( bacteria reproduce faster)
34
What are some of the plant barriers to pathogens
- tree bark
- waxy cuticle
- cellulose cell walls
- closing stomata
35
Define cell signalling
The coordination and communication between cells
36
Describe the process of cell signalling in plants in response to a pathogen
1) receptors in plant cells respond to molecules from pathogen made when plant cell is attacked
2) stimulates the release of signalling molecules
3) signalling molecules switch on genes in nucleus
4) this triggers a series of cellular responses:
- defensive chemicals
- defensive molecules to directly attack the pathogen
- callose and lignin made
37
Explain how callose is a plant defence
-When plants are infected by a pathogen they produce high levels of a polysaccharide called callose
-This is deposited between cell walls and cell surface membranes of cells next to infected cells
-they act as a BARRIER and prevent the pathogen entering cells around the site of infection
-Callose and lignin together make the barrier even thicker
-callose blocks sieve plates in the phloem sealing off the infected part
-deposited in the plasmodesmata to prevent spread
Acts as a matrix which antimicrobial compounds can be deposited in
38
Describe the structure of callose
Contains beta 1–3 and beta 1-4 glycosidic bonds
39
Name some chemical defences that plants produce
1) insect repellents- ie citronella
2) insecticides- caffeine is toxic to insects and fungi
3) antibacterial compounds- defensins
4) antifungal compounds- chitinases
5) anti oomycetes- glucanases
6) general toxins- cyanide
40
How do antibacterial compounds help a plant defend itself
Defensins- are plant proteins that disrupt bacterial/ fungal cell membranes
41
How do anti fugal compounds help plants defend themselves
Chitinases ( enzyme) hydrolyse chitin in fungal cell walls
42
How do anti oomycetes help plants defend themselves
Glucanases ( enzymes ) that break down glucans which are polymers found the cell walls of oomycetes
43
What is a oomycetes
A fungus like microorganism
44
How is cyanide toxic
Stops aerobic respiration
45
How is skin a primary non specific defence
- Covers the body and prevents the entry of pathogens
- Covered with a layer of healthy microorganisms which outcompete pathogens for space on the body surface
- Skin produces sebum
46
What is th importance of the skin producing sebum
An oily substance that prevents pathogen growth
| It is anti microbial
47
How do mucous membranes act as a primary non specific defence
- body tracts including airways of gas exchange are lined with these mucous membranes
- these secrete mucus which traps microorganisms and contain lysozymes which destroy bacteria and fungal cell walls
- mucus contains phagocytes which remove remaining pathogens
48
What is the job of lysozymes
Destroy bacteria and fungal cell walls
49
What are some expulsion reflexes
What are they an example of
- coughing
- Sneezing
- vomiting
- diarrhoea
These are examples of primary non specific defences
50
Describe wound repair
Platelets come into contact with collagen In wall of the damaged blood vessel, they adhere and start secreting substances including:
- thromboplastin
- factor X
- serotonin
Forms a blood clot- this dries out forming a scab
Epidermal cells beneath the scab start to grow sealing the wound permanently
Collagen fibres are deposited to give new tissue strength
Once epidermis is normal, scab sloughs off and wound is healed 🤯
51
What does thromboplastin do
It’s an enzyme that triggered a cascade of reactions resulting in a blood clot
52
What does serotonin do
Makes smooth muscle in the wall of blood vessel contract
53
What does factor X do
It’s an enzyme that is dependent on the co factor vitamin K is catalyses the conversion of prothrombin into the enzyme thrombin ( does this by altering the tertiary structure)
Thrombin then catalyses the conversion of fibrinogen into insoluble fibrin fibres which then forms the blood clot
54
What are some of the characteristics of inflammation
Pain
Heat
Redness
Swelling
55
Explain the cell signalling response to inflammation
1) mast cells bind to pat often
2) mast cells release histamine in local area
3) histamines bind to localised cells receptors
4) histamines make muscle in walls of blood vessels dilate
5) this triggers increased blood flow to area which makes capillaries more permeable to phagocytes
56
What do cytokines do
Stimulate hypothalamus to reset internal temperature to above 37 degrees - stops pathogen from reproducing
Cytokines attract white blood cells to the site
57
What are the two types of phagocytes
| Explain the difference
Neutrophils- released from bone marrow/ multi lobed nucleus
| Macrophages- released from lymph nodes
58
How can u identify from a blood smear a...
```
Platelet
RBC
Neutrophil
Monocyte
Lymphocyte
```
```
Platelet- very small only fragments of cell
RBC- no nucleus
Neutrophils- multi lobed nucleus
Monocyte- rounded nucleus
Lymphocyte- massive nucleus
```
59
Describe the process of phagocytosis
1) phagocyte receptors bind to pathogens antigen
2) pathogen is identified by antigens
3) pathogen is engulfed by phagocytosis into phagosome
4) lysosome fuses with phagosome releasing digestive enzymes
5) pathogen is hydrolyse into amino acids or glucose
6) useful material is absorbed into cytoplasm
60
Name the digestive enzymes in a phagolysosome
Lysins
61
What is phagocytosis an example of
Endocytosis
62
What are opsonins
Chemicals that bind to pathogens and tag them
Making them easily recognised by phagocytes
Phagocytes have receptors on cell surface membranes that bind to common opsonins
63
Give an example of an opsonins
Antibodies
64
How often do bacteria reproduce
Every 20 minutes
65
What type of pathogen is tuberculosis
Bacteria
66
What does tuberculosis do
Damages the lungs and suppressed immune system
67
Can tuberculosis be cured
Can it be prevented
Yes by antibiotics
Yes can have a Vaccination
68
How is tuberculosis transmitted
1) bacteria is transmitted in droplets
2) bacteria is encased in tubercle
3) bacteria are then dormant
4) bacteria destroy alveoli
5) leads to fibrosis/ scaring
6) reduces diffusion through less surface area
69
What factors increase the transmission of TB
- weakened immune system
- overcrowding
- poor diet
- homeless
70
How is bacteria released into the air
Through coughing and sneezing this can spread the disease to other organisms
71
3 reasons why TB has not been eradicated
- Antibiotic resistance
- Vaccine is less than 100% effective
- Developing countries can not afford treatment
72
What type of pathogen causes meningitis
Bacteria
73
How does meningitis affect the organism
Affects the protective membranes on the surface of the brain called meninges
74
What are some of the other diseases that can be caused through meningitis
Can spread to the rest of the body causing blood poisoning and death
75
Can meningitis be cured
Yes if antibiotics are delivered early enough
Can
76
What type of pathogen causes ring rot
Bacterial
77
What damage does ring rot cause
Damage to leaves, tubers and fruits
78
Is there a cure for ring rot
No
79
What do viruses do
```
Invade cells
Take over genetic machinery
Make cells they have infected make viral copies
Host cell bursts
Copies released
```
80
What does HIV stand for
Human immunodeficiency virus
81
What does AIDs stand for
Acquired immunodeficiency syndrome
82
What does the HIV virus affect
T helper cells of the bodies immune system
83
What does HIV have that helps it join with a T cell
Receptors
84
Why is HIV difficult to prevent
No cure
No vaccine
High mutation rate
Cannot be treated with antibiotics
85
Why is HIV more common in Africa
Poverty
Less education on disease transmission
Promiscuity
More intravenous drug abuse
86
What type of pathogen is influenza
Viral
87
What does influenza affect
Ciliates epithelial cells of the respiratory system
| These are killed and leads to secondary infection
88
what does a mutation cause
a change to the antigens on the surface of the cell
89
is there a vaccine for influenza
yes
| it is given to vulneraable groups annually
90
how do new strains emerge
influenza virus mutates and the antigens on the cell surface change. means that memory cells are not as effective and no antibodies for new antigen are produced
increases difficulty in producing vaccines
91
what are we doing about the flu
```
national vaccinations for vulnerable groups:
over 65yrs
weak immune system
infants
pregnant women
```
92
explain the difference between epidemic and pandemix
epidemic- when a disease is located in a particular area
| pandemic- when a disease is located across whole continents
93
what type of pathogen causes tobacco mosaic virus
virus
94
what does TMV cause
damage to leaves, flowers and fruit
causes a yellowing of leaves giving a mosaic pattern
stunts growth and reduces yield for farmers
95
describe protoctista
generally single celled
eukaryotes
enters cells and feeds on contents
96
what causes malaria
protoctista
| the plasmodium
97
what is the vector for malaria
female anopheles mosquito
98
what does plasmodium infect
erythrocytes , liver cells and the brain
99
is there cure and vaccine for malaria
no and no
100
list 3 ways how we can deal with malaria
pesticide spray
sleep under nets
antimalarial drugs
101
name the process of transmission of the plasmodium parasite
1) female anopheles mosquito bites and releases saliva containing the plasmodium into the blood
2) plasmodium multiply in liver cells and are released back into the blood
3) gametes released into the blood
4) gametes taken into the female anopheles stomach on feeding
5) gametes fuse to form zygotes and then plasmodium in salivary glands
102
why is malaria such a problem
5 different species of plasmodium parasite
103
what is the cause of potato and tomato blight
protoctista ( the protoctist oomycete)
104
how does an oomycete differ to a fungus
cell wall made of cellulose in oomycete
105
what does the hyphae in potato and tomato blight do
penetrates host cell which causes destruction to leaves fruit and tubers
106
what does fungi send out, what does this cause?
reproductive hyphae which produce spores which can cause redness and irritation
107
what type of pathogen causes black sigatoka
fungi
108
what does black sigatoka do
causes black streaks in leaves and the fungus digests the leaves
109
what are some of the consequences of black sigatoka
reduces the plants ability to carry out photosynthesis
110
what is used to kill the fungus
fungicides
111
what type of pathogen causes ring worm
funghal
112
what does ring worm cause and what does this lead to
a scaly crusted rash that may appear as round, red patches on the skin
leads to itching and blister like lesions
113
how is ringworm cured
by using antifungal creams
114
what type of pathogen causes athletes foot
fungal
115
what is athletes foot a type of
ring worm
116
what does ring worm produce
enzymes that digest the skin
117
how is ring worm cured
using anti fungal creams
118
What type of pathogen causes athletes foot
Fungal
119
Where does the fungus in athletes foot live
In between the toes where it is moist and warm
120
What does the fungus in athletes foot produce
Enzymes that digest the skin
121
Define non self antigen
A glycoproteins on the surface of a pathogen which causes an immune response
122
Define self antigen
A glycoproteins on cell surface membrane of body cells
The immune system recognised these cells as self
123
How many polypeptides in an antibody
What bond holds them together
4 polypeptides ( 2 light and 2 heavy)
Disulphides bridges
124
What is the variable region specific to
That particular antibodies primary structure
125
What part of the antibody bonds to phagocytes
Constant region
126
What does the hinge region allow
Flexibility
127
What are the two functions of antibodies
Neutralisation and agglutination
128
What does neutralisation mean
Antibodies covering the pathogen binding sites prevent the pathogen from binding to a host cell and entering the cell
129
What does agglutination mean
A large antibody can bind many pathogens together
This makes them too large to enter a host celll
130
What are anti toxins
Antibodies that can also hind to toxins made by some pathogens this renders them harmless
131
What does complement cascade mean
Complement proteins in the blood interact with the bacterial cell surface membrane and form holes in it
132
What do the job of a macrophage
Engulf and digest pathogens in lymph nodes and present antigens on cell surface membrane
133
What is the job of a neutrophil
E gulf and digest pathogens in the blood around the body
134
Where do t- helper cells mature
In the thymus gland
135
Name the type of receptors on t helper cells
What do these do
CD4 receptors
They bind to the antigens presented on APCs
136
Once activated what do t helper cells release
What do they do
Interleukins
Stimulate the T cells to divide by mitosis
Interleukins also cause b-lymphocytes to divide by mitosis and stimulate the process of phagocytosis
137
What do cloned t. Cells divide into
T killer cells
| T memory cells
138
What do t killer cells produce
Toxin hydrogen peroxide to kill infected cells
And perforin that makes holes in the cell surface membrane
139
What else do t memory cells do
They form the immunological memory
Live for a long time
Develop from cloned T cells as a result of cell mediated immunity
140
What do t regulator cells do
Controls and regulates the immune system
Stop immune system once a pathogen has been eliminated
Prevents autoimmune disease- when immune system doesn’t recognise self antigens correctly it starts to destroy its own cells/ tissues
141
What do the t helper cells do
Activated b lymphocytes at the start of the humoral response
Made in cell mediated immunity
142
Where do b lymphocytes mature
In the bone marrow
143
What do b lymphocytes do
Divide by mitosis to form cloned B cells that make lots of B memory cells and plasma cells
144
What are the 4 key communication methods
Identification- antigen acts as a ID indicating whether it is foreign
Presentation- antigens presented on membranes
Distress signals- pathogen May be placed into the cell surface membrane which tells the t killer lymphocytes to destroy it
Instructions- cytokines released by cells allow communication and coordination between cells
145
What are the two processes interleukins stimulate
B cells to divide
Development of t killer cells
Phagocytosis
146
What is the job of an interferon
Stimulates t killer cells and inhibits virus replication
147
What is the job of plasma cells
What causes this
Produce antibodies
Cytokines
148
Describe the shape of the receptors for cytokines on b lymphocytes
Complementary
Activated the mitosis of B lymphocytes
149
What type of lymphocyte is involved with cell mediated immunity
T lymphocytes
150
Describe the process of cells mediated immunity
1) macrophages engulf and digest pathogens
2) macrophages process antigens from pathogens and present them on their surface
3) some of the t helper cells have receptors that fit the antigen. They become activated (CLONAL SELECTION)
4) cloned T cells formed by (CLONAL EXPANSION)
5) develop into t memory cells or t killer cells
Produce interleukins which stimulates B cells to divide
151
Describe the process of humoral immunity
1) antibody on surface of a B cell binds to antigens
B cells processes antigens and presents them on the surface of their cell
2) activated t helper cell bunds to antigens on B cell APC ( CLONAL SELECTION)
3) interleukins produced by activated t helper cell activate B cell
4) activated B cells divide by osmosis (CLONAL EXPANSION)
5) clone cells form plasma or memory cells
6) plasma cells produce antibodies
152
Define CLONAL selection
When a T cell or a B cell has a matching receptor to the antigen
153
What is CLONAL expansion
When the selected T cell or B cell divided by mitosis to make many clones
154
What type of pathogen does the humoral response involve
B lymphocytes
155
What does the humoral system produce
Antibodies
156
How do each of the following help the fight of pathogens
Macrophages
Plasma cell
Killer T Cells
Macrophages Engulf and digest pathogens
Plasma cells produce antibodies
Killer T cells produce h-peroxide and preforin
157
What response is used for
Intracellular
Extra cellular
Intracellular - cell mediated immunity
| Extracellular- humoral mediated immunity
158
Define immunity
The ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitised white blood cells
159
Describe natural active immunity
When you meet a pathogen for the first time you produce T + B memory cells
When u meet these again your immune system recognises antigens
Large quantities of the appropriate antibody are made very quickly
160
Describe natural passive immunity
Antibodies cross the placenta when the developing foetus is in the uterus
Also passed on in breast milk
161
Describe artificial passive immunity
Antibodies are made in one organism, extracted and injected into another organism
Treatment is instant
162
Describe artificial active immunity
Vaccination
Small amounts are injected into the blood
Triggers primary immune response
Memory cells are made
163
How does a vaccination work
1) contain antigens in vaccine
2) usually injected ( if taken orally could be broken down by enzymes)
3) cause antibody production and memory cells
4) makes u less likely to suffer
164
Define epidemic
Where disease is located in a particular area
165
Define pandemic
Where a disease is located across continents
166
What happens in an autoimmune disease
The immune system stops recognising cells of body as being ‘self’ so attacks its own healthy tissue
167
Why are some of the reasons an autoimmune disease may develop
There is a genetic link
Immune system responds abnormally to a mild pathogen
T regulator cells are not working right
168
Name three examples of autoimmune diseases
Type 1 diabetes
Rheumatoid arthritis
Lupus
169
What are some of the ways new drugs can be developed
Plants, chemicals, microorganisms
Scientists also use computer programmes to design drugs
Genetic engineering- some mammals have been re engineered to produce drug in their milk
170
What is pharmacogenetics
Where scientists will look at the patients genome and consider it for any weaknesses
Scientists will look for specific cancer causing genes and treat it with specific drugs
171
What are humans doing that is damaging our potential access to new drugs
Deforestation and climate change- species going extinct
172
Name the 5 ways how antibiotics work
1) disrupt the cell wall
2) disrupt membranes
3) inhibit protein synthesis
4) inhibit dna/rna processes
5) disrupt metabolism
173
How do animals spread antibiotic resistance
They are fed antibiotics- develop resistance in there gut
The meat that is not taken from them may have this resistance on it and when not handled properly bacteria can spread to humans
174
How can a person develop antibiotic resistance
Are given antibiotics
Develop resistance in there gut
Spread it to the local comminuty
Or go to hospitals and spread it to patients there
175
Name three causes of antibiotic resistance
1) over prescribing antibiotics
2) lack of hygiene
3) lack of new antibiotics developed
