Communicable Diseases Flashcards
1
Q
What is a pathogen
A
An organism that causes disease
2
Q
What is a host
A
The organism that a pathogen lives increases
3
Q
What are the different types of pathogens
A
- bacteria
- fungi
- viruses
- protists
4
Q
What kingdom does bacteria belong to
A
Prokaryotae
5
Q
What is a mycelium
A
Root like structure of a fungus consisting of a mass of branched hyphae
6
Q
What are hyphae
A
Each of the branches that make up the mycelium of fungus
7
Q
What do specialised reproductive hyphae do
A
- grow to the surface of the skin
- release spores
- causes redness and irritation
8
Q
Where does fungus live in plants
A
Vascular tissue
- able to gain nutrients
9
Q
What do the hyphae release in plants
A
Extracellular enzymes
- digest the surrounding tissue
- causing decay
10
Q
How do viruses work
A
- invade cells
- take over genetic machinery and other organelles in the cell
- cause the cell to manufacture copies of the virus
11
Q
What happens to the cell that a virus invades
A
Eventually bursts
- releases more new viruses that will infect other healthy cells
12
Q
What do protists do
A
Enter the host cells
- feed on the contents as they grow
13
Q
Characteristics of tuberculosis
A
A disease that infects many parts of the body
- kills the cells and tissues
- most often effect the lungs
14
Q
Characteristics of bacterial meningitis
A
Infection of the meninges - membrane that surrounds the brain and spinal cord
- membranes swell up
- cause damage to the brain and nerves
15
Q
Characteristics of ring rot (plants)
A
Ring of decay in the vascular tissue
- potato tubur or tomato
- leaf wilting
16
Q
Characteristics of HIV/AIDS
A
Attacks cells in the immune system
- compromises the immune response
17
Q
Characteristics of influenza/flu
A
Attacks respiratory stems
- causes muscle pains and headaches
18
Q
Characteristics of tobacco mosaic virus
A
Causes mottling and discolouration of leaves
19
Q
Characteristics of black Sigatoka (bananas)
A
Causes leaf spots of banana plants reducing yield
20
Q
Characteristics of blight (tomatoes and potatoes)
A
Affects both leaves and potato tubers
21
Q
Characteristics of ringworm (cattle)
A
Growth of fungus in skin with spore cases erupting through skin to causes a rash
22
Q
Characteristics of athlete’s foot (humans)
A
Growth under skin of feet
- particularly between the toes
23
Q
Characteristics of malaria
A
Parasite in the blood that causes headache and fever
- may progress to coma and death
24
Q
What organism causes tuberculosis
A
Bacteria
25
What organism causes bacterial meningitis
Bacterai
26
What organism causes ring rot (plants)
Bacterium
27
What organism causes HIV/AIDS
Virus
28
What organism causes influenza/flu
Virus
29
What organism causes tobacco mosaic virus
Virus
30
What organism causes black Sigatoka (banana)
Fungus
31
What organism causes blight (tomatoes and potatoes)
Protists
32
What organism causes ringworm (cattle)
Fungus
33
What organism causes athlete’s foot (humans)
Fungus
34
What organism causes malaria
Protists
35
What is the lifecycle of pathogens
- travel from one host to another (transmission)
- entering the host’s tissues
- reproducing
- leaving the host’s tissues
36
What are the different types of transmission between animals
- direct
- indirect
37
Examples of direct transmission
- direct physical contact
- faecal-oral transmission
- droplet infection
- transmission by spores
38
What factors effect direct physical contact transmission
- hygiene
- keeping surfaces clean
- cleaning/disinfecting cuts
- sterilising surgical instruments
- condoms
39
What factors effect faecal-oral transmission
- human sewage to fertilise crops
- treatment of waste water
- thorough washing of fresh fruit
40
What factors effect droplet infection transmission
- cover mouth when coughing or sneezing
- catch it, bin it, kill it
41
What factors effect transmission of spores
- mask
- washing skin after contact with soil
42
Factors that affect transmission
- overcrowding
- poor ventilation
- poor health
- poor diet
- homelessness
- living or working with people who have migrated from areas where a disease is more common
43
How are pathogens transmitted indirectly
Vectors
44
What is a vector
Another organism that may be used by the pathogen to gain entry to the primary host
45
What conditions improve pathogen reproduction
Warm and moist conditions
46
What is callose
A large polysaccharide deposit that blocks old phloem sieve tubes
47
Examples of passive defenses in plants
- physical defenses
- chemical defenses
48
What are passive defenses in plants
Defenses present before infection
- prevent entry and spread of pathogens
49
Examples of physical defenses in plants
- cellulose cell wall
- lignin thickening of cell wall
- waxy cuticle
- bark
- stomata closure
- callose
- tylose formation
50
What is a tylose
Ballon like swelling or projection that fills the xylem vessel
51
Examples of chemical defenses in plants
- terpenoids
- phenols
- alkaloids
- hydrolytic enzymes
52
What is active defense in plants
After the pathogen has attacked
- plants response
53
Examples of active defenses in plants
- thickened cell walls
- deposit of callose
- oxidative bursts
- increased production of chemicals
- necrosis
54
What are oxidative bursts
Able to produce highly reactive oxygen molecules capable of damaging the calls of invading organisms
55
What does terpenoids do
Essential oils that have antibacterial and antifungal properties
56
What do phenols do
- antibiotic/anti fungal properties
- inhibit attack by insects by deactivating their digestive enzymes
57
What does alkaloids do
Nitrogen containing compounds that give a bitter taste to the plant
- caffeine
- nicotine
- cocaine
- morphine
58
What are defensive proteins (defensins)
Small cysteine-rich proteins
- broad anti-microbial activity
59
What are hydrolytic enzymes
Found in the spaces between cells
- include chitinases, glucanases, lysozymes
60
What is necrosis
Deliberate cell suicide
61
Examples of primary defenses against disease in animals
- skin
- blood clotting/skin repair
- mucous membranes
62
What are primary defenses
- mechanisms that prevent the entry of pathogenic organisms
- non specific
63
What are keratinocyte cells
Cells produced by mitosis at the base of the epidermis
- move up to surface of skin
- cytoplasm is replaced by keratin
64
What is the main type of cell in the skin
Keratinocyte cells
65
What is keratinisation
The process of keratin entering the keratinocyte cells
66
How long does keratinisation take
30 days
67
What activates an enzyme cascade in blood clotting
Clotting factors
68
What does a scab do to fibrinogen
Turn it into fibrin
69
Why do scabs turn fibrinogen into fibrin
Soluble fibrinogen from plasma into insoluble fibrin
70
What is the mucus membrane made out of
Mixture of epithelium cells and mucus secreting cells (goblet cells)
71
What are macrophages
Larger cells made in the bone marrow
72
What are monocytes
Macrophages traveling through the blood
73
Where are monocytes found
Lymph nodes
74
What is the role of macrophages
Initiate the specifics responses to invading pathogens
- engulf pathogens
75
What is an antigen-presenting cell
When the antigen from the surface of a pathogen is saved and moved to a special protein complex on the surface of the cell
76
What are secondary defences
Used to combat pathogens that have entered the body
77
What are antigens
Chemical markers on its outer membrane
78
What are opsonins
Proteins molecules that attach to the antigens on the surface of a pathogen
- type of antibody
79
What is the role of opsonins
To enhance the ability of phagocytise cells to bind and engulf pathogens
80
What are phagocytes
Specialised cells in the blood and tissue fluid that engulf and digest pathogens
81
Where are neutrophils made
Bone marrow
82
Lifespan of neutrophils
Short lived
83
What do neutrophils contain a lot of
Lysosomes
84
What is the role of antigen presenting cells
Move around the body until it comes into contact with specific cells that can activate the full immune response
85
What are the cells antigen presenting cells are looking for
- t lymphocytes
- b lymphocytes
86
What is the role of antigen presenting cells
Increase the chance of antigens coming into contact with t/b lymphocytes
87
What is clonal selection
Activation of specific B and T cells
88
What are cytokines
Hormone-like chemicals that stimulate and coordinate the specific immune response
- stimulate differentiation and activity of macrophages, B cells and T cells
89
What does the immune response produce
Antibodies
90
What do antibodies do
Neutralise foreign antigens
91
How is immunological memory maintained
Production of memory cells
92
What cells are produced in the immune response
- T helper cells
- T killer cells
- T memory cells
- T regulatory cells
- Plasma cells
- B memory cells
93
What are T helper cells
Release cytokines that stimulate B cells to develop and stimulate phagocytosis by the phagocytes
94
What are T killer cells
Attack and kill host-body cells that display the foreign antigens
95
What are T memory cells
Provide long-term immunity
96
What are T regulator cells
Shut down the immune response after the pathogen has been successfully removed
- also involved in preventing autoimmunity
97
What are plasma cells
Circulate in the blood, manufacturing and releasing the antibodies
98
What are B memory cells
Remain the the body for a number of years and act as the immunological memory
99
How is cell communication achieved
Release of hormone-like chemicals called cytokines
100
Examples of communications using cytokines
- macrophages release monokines
- T cells and macrophages release interleukins
- many cells can release interferon
101
What are interleukins
Stimulate clonan expansion and differentiation of B and T cells
102
When does an autoimmune disease occur
When the immune system attacks a part of the body
- antibodies start to attack our own antigens
103
What is clonal expansion
Once the correct lymphocytes have been activated they must increase in numbers to become effective
- achieved my mitotic cell division
104
What are the steps of phagocytosis
- phagocyte recognises non-self antigen and binds to the pathogen
- pathogen engulfed through extension of pseudooedia (flexibility in lipid bilayer)
- enclosed in phagosome
- vacuole fuses with lysosome to form phagolysosome
- lysosome contains hydrolytic enzymes
- pathogen is digested/hydrolised
105
What are the different types of antibiotics
- bactericidal
- bacteriostatic
106
What do bactericidal antibiotics do
Kill the bacteria
- gram positive
107
What do bacteriostatic antibiotics do
Prevent the bacteria from reproducing
- gram negative
108
What are non-specific immune responses able to do
Destroy multiple different types of pathogen
109
Where do T-lymphocytes mature
Thymus
110
What is active immunity
When the body produces the antibodies
111
What are passive immunity
Antigens are made artificially
112
What are the functions of the antibodies
- act as antitoxins
- cause aggulation of the pathogen (cause them to clump together)
- serve as markers (opsonisation ) = stimulate the phagocytes to engulf when attached to pathogen
113
What type of molecule is an antibody
Protein
114
Steps to producing monoclonal antibodies
- antigen is injected into a mouse
- produce plasma cells
- plasma cells are mixed with tumour cells
- produce hybridoma cells
115
Examples of primary non-specific defences
- skin
- blood clotting
- wound repair
- inflammation
- mucous membranes
