4.1 Communicable Diseases Prevention And The Immune System Flashcards
(104 cards)
1
Q
What is a communicable disease?
A
Caused by one organism that infects another and is passed on organism to organism
2
Q
What are bacteria, how does it infect and what causes illness?
A
- Living pathogens
- Prokaryotes
- From infected to infected usually through infected droplets but also direct contact
- Releases toxins
3
Q
What are viruses,how do they infect and what causes illness?
A
- None living
- Enters cells through being inhaled or ingested
- Infect cells by inserting RNA then produces proteins causing them to burst out of the cell
4
Q
What are protists, how does it infect and what causes the illness?
A
- Eukaryotic,living cells
- Infects via vector but can also be directly transmitted
- They take over a cell,digest insides then burst out
5
Q
What are fungi,how do they infect and what causes illness?
A
-Non living eukaryotes
- Can be multicellular
- Produces spores
- Digest and destroy living cellss
6
Q
What is direct transmission in plants?
A
Direct contact of healthy plant to diseased plant
7
Q
What is indirect transmission of disease in plants?
A
Can occur through soil contamination or via vectors
8
Q
What is soil contamination?
A
Infected plants can leave pathogens or reproductive spores in soil
9
Q
What vectors are there for plant disease?
A
Wind- pathogens can be carried
Water- spores can be held by water tension in water
Animals- insects and birds carry pathogens from one plant to another as they feed
Humans- transmitted on tools and clothing
10
Q
What factors affect transmission of plant disease?
A
- More susceptible varieties
- Overcrowding
- Poor mineral nutrition reduces resistance
- Damp warm conditions
- Climate change
11
Q
What is the name of the organism that causes ring rot?
A
Clavibacter Michiganessis Bacteria
12
Q
How is ring rot transmitted?
A
- Indirect
- Remains in soil and contaminates it
- Also infected seed tubers
13
Q
What factors affect transmission of ring rot?
A
- Unsanitised machinery
- Insects
14
Q
What is the name of the organism that causes TMV?
A
Tobacco Mosaic Virus
15
Q
How is TMV transmitted?
A
In the air
Contact with infected plant
Indirect and direct transmission
16
Q
What factors affect transmission of TMV?
A
Contaminated hands/ lack of sanitatiom
17
Q
What organism causes potato blight?
A
Phytophtora Infestans Protocist
18
Q
How is potato blight transmitted?
A
- By hyphae penetrating host cells
- Sporagia (hyphae) are dispersed by rain then the wind and spores are released
- Indirect
19
Q
What factors affect transmission of potato blight?
A
- Wind
- Wet weather increases transmission
20
Q
What is the organism that causes black Sigatoka?
A
Mycosphorella fijiensis Fungi
21
Q
How is black Sigatoka pathogen transmitted?
A
- Airborne and in water
- Hyphae penetrate and digest cells
22
Q
What is a passive defence in plants?
A
Present before infection to prevent entry and spread of pathogen
23
Q
Examples of passive plant defences?
A
- Waxy cuticle- prevents water from collecting (reduces likelihood of pathogen lingering)
- Bark- Contains chemical defences but also a physical barrier
- Cellulose cell walls- Barrier + Lignin which are almost indigestable
24
Q
What are active defences in plants?
A
Pathogens can be detected by chemicals on their cell wall the plant responds by fortifying its defences
25
What examples are there of active defences in plants?
- Guard cell- Close stomata if pathogens are detected=barrier
- Callose- Blocks sieve plate and flow in sieve tube to prevent pathogen travelling around plant
- Tylose- Swelling that fits xylem to plug vessels and contains terpene chemicals which are toxic
26
What is necrosis?
- Deliberate cell suicide which saves rest of plant
- Means that pathogens access to water and nutrients is limited
27
What do antiseptics do?
Destroy cell walls using enzymes
28
What do antifungal things do?
Chithases break down cell wall
29
What do antioomycytes do?
Breakdown glucans in cell wall
30
What bacteria causes Meningitis?
Streptococcus Pneumonae
31
How does meningitis affect the body?
Infects the meninges in the Brain which can cause septicaemia
32
What are the symptoms of meningitis?
- Blotchy rash
- Fever
- Aches
33
How is meningitis transmitted and what increases the risk of transmission?
- Infected droplets which are then inhaled
- Overcrowding,young people and lack of sanitation
34
How can spread of meningitis be controlled?
- Antibiotics
- Vaccines
35
What causes HIV?
Human immunodeficiency virus
36
What are the symptoms of HIV?
- Flu like symptoms
- Aches
- Fever
37
How is HIV transmitted and what increases risk factors?
- Contact of bodily fluids
- Unprotected sex, sharing needles
38
How can spread of HIV be reduced?
- Contraception
- Sex Education
- Antiretroviral
39
What pathogen causes TB?
- Mycobacterium Tuberculosis
- Bacteria
40
What does HIV do to the cells?
- Targets T helper cells of the immune system destroying them
41
What does TB do to the body?
- Damages and destroys lung tissue
- Suppresses immune system
42
What are the symptoms of TB?
- Coughing and sneezing
- Fever
- Loss of appetite
43
How does TB spread, what increases risk of transmission and how can it be reduced?
- Infected droplets
- Overcrowding,underserved groups (homeless)
- Latent TB can be treated, curable with treatment
44
What causes influenza?
Virus
45
How does Flu affect the body?
- Infects ciliated epithelial cells in gas exchange system
46
What are the symptoms of flu?
- Coughing
- Aches
- Sneezing
47
How is flu transmitted,what increases transmission and how can it be reduced?
- Infected droplets
- Lack of sanitation and Overcrowding
- Personal hygiene,flu vaccine and PPE
48
What causes athletes foot?
Fungus
49
How does athletes foot affect the body?
Grows and digests warm skin between toes
50
What are the symptoms of Athletes foot?
- Itchy feet
- Cracking and scaling on toes
51
How is athletes foot transmitted,what increases the risk and how can spread be reduced?
- Contact with fungus on floors
- Damp shoes and socks and sharing shoes
- Keep feet dry, wash feet and wear shower shoes
52
What causes ringworm?
Fungus
53
How does ringworm affect the body?
-Affects skin
54
What are the symptoms of ringworm?
- Round/oval red patches
- Flaky skin
- Itchy skin
55
How is ringworm transmitted,what increases the risk and how can spread be reduced?
- Contact with fungus via belongings
- Damp conditions
- Avoid sharing personal belongings, keep area clean and dry,antifungal medication
56
What causes malaria?
Protist - Plasmodium
57
How does malaria affect the body?
- The blood where it inserts into cells and digests haemoglobin
58
What are the symptoms of malaria?
- Anaemia
- Inflammation
- Liver damage
59
What are the means of transmission,risk factors and how can spread of malaria be reduced?
- Bites from infected mosquitoes
- Young people,tropical regions
- Insecticides,mosquito nets,window and door screens,anti malarial drugs
60
What non specific barriers do animals have for pathogens?
- Skin- Physical barrier + Sebum which inhibits pathogen growth
- Skin flora- population of non pathogenic bacteria
- Mucous membranes- traps pathogens
- Lysozymes- In tears,urine and stomach acid which destroy pathogens
61
What happens when skin is ruptured?
- Clotting
62
What are the stages of clotting?
- Platelets rush to site and release Thromboplastin and Serotonin
- Platekets along with blood cells attached dries out preventing pathogens entering
- Epidermal cells grow beneath scab reinforced with collagen
63
What are the characteristics of the inflammatory response?
- Redness and swelling around injury site
64
What is the order of events inside the body when a splinter enters?
- Marker cells release histamines which dilate and increase permeability of capillaries endothelial wall
- Neutrophils can then exit capillaries into tussle by cytokines drawing neutrophils to the walls.
65
What is the expulsive reflex?
- Pathogen laden bodily fluids are ejected
- Vo,icing and diarrhoea
66
What causes a fever?
Cytokines cause hypothalamus to reset so body temperature can rise higher than 37c
67
Why are fevers effective at reducing pathogens?
Pathogen cannot reproduce as quickly and the specific immune system can move faster
68
What are the steps of phagocytosis?
1. Phagocyte attracted to pathogen due to chemicals produced by pathogens
2. Phagocyte will then recognise antigen on pathogen and bind to it
3. Phagocyte engulfs pathogen putting it in special vacuole called a phagosome
4.Phagosome combines with lysosome forming phagolysosome
5. phagolysosome uses enzymes to break down pathogen
6. Broken down pathogen is either moved out by exocytosis or absorbed by phagocyte antigens to combine with MHC
69
What happens if the digested pathogen in phagocytosis is absorbed by antigens to combine with MHC?
The MHC/ antigen complex on phagocyte membrane making an antigen presenting cell.
70
What is the role of an antigen presenting cell?
To stimulate other immune cells?
71
What are the role of cytokines?
Produced by phagocytes
Inform phagocytes about pathogen
Stimulate increase in body temp
72
What are opsonins?
- Bind to pathogens and tag them so they can be more easily recognised
- Received by receptors in cell membrane
- Phagocyte then engulfs pathogens
73
What is the definition of a parasite?
- Cannot work independently of host
- Harms the host
- Lives in host
74
How do you count blood cells?
Overlay image with acetate that has squares on it and count those in certain area
75
What is a macrophage?
- Phagocytic cell that consumes foreign pathogen
- Stimulates other immune cells
- Migrates from blood vessels to tissue
76
What is a natural killer cell?
- Kills tumour cells and virus-infected cells
- Circulates in blood and migrates into tissues
77
What is a neutrophil?
- First responders at the site if infection
- releases toxins that kill or inhibit bacteria
78
What bond holds the chains of an antibody together?
Disulphide bridge
79
What is special about the binding site of an antibody?
Specific shape to be complimentary to an antigen on a pathogen
80
What is the purpose of the hinge region (squiggles on diagrams that hold the heavy chains together)?
So the antibody can flex
81
What is the purpose of the constant region of an antibody?
Binding to phagocytes
82
What is neutralisation by antibodies?
- Antibodies bind to antigens on pathogen membrane preventing it from attaching and entering host cells
- Also encourage macrophages to phagocytose
83
What is agglutination?
- Uses each binding site to attach to a different antibody which forms a large clump
- Non infective and easily phagocytosed
84
What is agglutination?
- Antibody binding site bind different pathogens together forming a large flu,p
- non infective and easily phagocytosed
85
What isopsonisation?
The end of the antibody stimulates phagocytosis
86
What is the action of an antitoxin?
Removes risk of toxins
87
What is immunological memory?
1. Antibodies produced several days after initial infection = small response
2. Second infection = longer,faster and larger immune response
- Antigen specific
88
What are plasma cells?
- Make antibodies
- Have lots of:
1. Rough ER for synthesising a lot of antibodies
2. Lots of mitochondria for ATP for exocytosis and making antibodies
3. Golgi apparatus- Packaging antibody proteins
89
Where do B lymphocytes mature?
The bone marrow
90
Where do T lymphocytes mature
The thymus gland
91
What is the order of humoral immune response?
1. B cell becomes an APC after phagocytosis
2.APC interacts with specific Th cell releasing interleukin 1
3. Interleukin 1 stimulates interleukin 2 which causes differentiation of effector B cells into plasma cells
4. Plasma cells divide and produce a large number of antibodies
5. Effector B cells become memory b cells in case of further infection
92
What are the steps of the cellular immune response?
1. Macrophage becomes an APC after phagocytosis
2. APC interacts with a specific Th cell and release interleukin 1
3. Interleukin 1 stimulates release of interleukin 2 which stimulates growth of cytotoxic cells
4. Cytotoxic cells detect antigen on surface of infected cells and produce perforin which makes the membrane more permeable and causes cell lysis
5. Memory T cells are produced in case of further infectoon
93
What are T regulator cells?
- Prevent an auto immune response by repressing the immune system after all the pathogens have been destroyed
94
What is an example of a natural active response?
- Normal immune response
95
What is an example of natural passive immune response?
- Newborn babies immune system is taken from their mother from breast,ilk and across the placenta
96
What is an artificial active immune response?
- Vaccination
97
What is an artificial passive immune response?
- Antibodies produced by another organism and injecting into blood
- e.g, Tetanus
98
What types of antigen can vaccines contain?
- Killed or inactive bacteria and viruses
- attenuated (weakened) strains
- toxin molecules that have been altered and detoxified
- Isolated antigens extracted from pathogen
- genetically engineered antigen
99
What is an auto immune disease?
When the body fails to recognise the body’s own cells as itself resulting in damage to healthy cells
100
What is an example of autoimmune disease?
Lupus,Rheumatoid arthritis, Coeliac disease
101
What is antigenic variation?
Antigens displayed on the virus mutate meaning a new virus strain has emerged
102
What is herd immunity?
- Where enough people are vaccinated to provide immunity to at risk population
103
What is selective toxicity?
Interferes with a pathogen while not affecting surrounding cells
104
What is genetic screening?
Seeing what genes people have
