Communicable Diseases Flashcards
1
Q
What’s an infectious disease?
A
A disease resulting from infection of a host organism by a pathogen
2
Q
What are the four types of pathogens?
A
Bacteria
Viruses
Fungus
Proctists
3
Q
How big are fungi?
A
10-100 micro metres
4
Q
How big are bacteria?
A
0.5 - 20 micrometres
5
Q
How big is a virus?
A
20 - 250 nanometres
6
Q
Are bacteria eukaryotes?
A
No
they’re prokaryotes
7
Q
What shapes can bacteria be?
A
Cocci
Spirilli
Bacilli
Vibrio
8
Q
How do
A
9
Q
What is the process where bacteria reproduce?
A
Binary fission
10
Q
How is binary fission different do mitosis?
A
DNA replication and DNA separation occurs at the same time in binary fission
There’s no mitotic spindle
11
Q
Are viruses living?
A
No viruses are regarded as non-living
12
Q
How do viruses reproduce?
A
Use host cells to reproduce rapidly and evolve by developing adaptations to their host
13
Q
What is a virus that attacks bacteria?
A
Bacteriophages
14
Q
Is a protist prokaryote?
A
No
It’s eukaryotic
15
Q
What kind organisms are protists?
A
Single celled organisms and cells that live in colonies
16
Q
What is a small group of proctista?
A
They act as pathogens
They are parasites so they use the host organisms for their benefit
17
Q
How do proctista use the host organism?
A
Use the host organism for their benefit
18
Q
What do many protists require?
A
Many require a vector to transfer to their host
19
Q
Where can fungus live?
A
Skin of an animal
It’s hyphae which form a mycelium
20
Q
What does hyphae do in a fungus?
A
Reproductive hyphae grow to the surface of the skin to release spores
Causing redness and irritation
21
Q
Can fungi photosynthesise?
A
No
They have to digest their food extracellularly
22
Q
How do fungi digest their food?
A
Extracellularly
23
Q
What is a saprophyte?
Fungi are saprophytes
A
Something that feeds of dead and decaying matter
24
Q
How do pathogens cause disease?
A
-Damaging host cells or tissues directly
-producing toxins which damage body tissues
25
When are exotoxins produced?
Exotoxins are produced and secreted by a normal pathogen
26
What are endotoxins?
They are produced when a pathogen is damaged and toxins are released
27
What pathogen is Tuberculosis?
Bacterium
28
What pathogen is Ring Rot?
Bacteria
29
What pathogen is HIV/AIDS?
Virus
30
What pathogen is influenza?
Virus
31
What pathogen is tobacco mosaic virus?
Virus
32
What pathogen is black Sigatoka?
Fungi
33
What pathogen is athletes food?
Fungi
34
What pathogen is potato/tomato blight?
Protoctist
35
What pathogen is a malaria?
Protoctist
36
What does ring rot affect?
Humans
Cattle
Other animals
37
What does ring rot affect?
Potatoes
Tomatoes
38
What does HIV / AIDS affect?
Humans
39
What does influenza affect?
Animals
Humans
40
What does tobacco mosaic (TMV) affect?
Plants
41
What does black Sigatoka affect?
Bananas
42
What does athletes foot affect?
Humans
43
What does potato/tomato blight affect?
Potatoes
Tomatoes
44
What does malaria affect?
Humans
Animals
45
What does tuberculosis do?
-Damages and destroys lung tissue
-Suppresses the immune system
-Leaves the body susceptible to other diseases
46
Is TB curable?
Yes antibiotics
And preventable by vaccinations and improvement of living standards
47
What symptoms does ring rot cause?
Ring of decay in vascular tissue and leaf wilting
48
What kind of bacteria causes ring rot?
Gram positive
49
What does AIDS stand for?
Acquired immunodeficiency syndrome
50
What does HIV stand for?
Human immunodeficiency Virus
51
What does HIV do?
The virus targets T helper cells in the immune system.
It gradually destroys the immune system
Leaving people susceptible to other infections
52
Is there a cure for HIV / AIDS?
no
No vaccine or cure
But there are trials
53
What does influenza do?
It’s a viral infection of the ciliated epithelium cells in the gas exchange system.
It kills the cells
Leaves the airways open to secondary infection (can lead to pneumonia)
54
What does TMV do?
Virus that spreads between dells via the plasmodesmata or through the phloem to the rest of the plant
Causes mottling on leaves
55
What are the symptoms and info about black Sigatoka?
Caused by a fungus which attacks and destroys the leaves on bananas
The hyphae penetrate and digest the cells
Turns the leaves the black
56
How does athletes foot work?
A fungal infection
It grows and digests the warm, moist skin between the toes
It causes cracking and scaling
Itchy and sore
Anti fungal creams and powders
57
Info about potato/tomato late blight?
Caused by a Protoctist
Affects the tuber or fruit with necrotic brown lesions l
Causes lesions on leaves
58
Info about malaria?
-caused by the Protoctist plasmodium
-spread by female mosquito bites
- it invades liver cells
-red blood cells
-the brain
-causes severe fevers, headaches and exhaustion
59
Is there a cure for malaria?
No vaccine
No cure
There are preventative measures to control the vector
-removing still water
-mosquito nets
-insecticides
60
What are the two types of disease transmission?
Direct
Indirect
61
In plants, where does the fungus live?
Often live in the vascular tissue
62
how do fungi reproduce when conditions are harsh?
they produce millions of tiny spores which can spread huge distances
63
how do pathogens reduce the rate of photosynthesis?
blocking light
destroying chloroplasts
64
how do pathogens increase rate of respiration?
the rate of respiration increases as plants fight the infection
65
how can pathogens make plants lose water?
they may lose water through wounds
66
how can pathogens impact the xylem and phloem?
pathogens can block xylem and phloem
67
how can farmers prevent the spread of communicable diseases in plants?
leave space between plants
rotate crops
clear fields thoroughly after harvest
follow strict hygiene procedures
control insect vectors
68
what kind of defences to plants have against pathogens?
plants have passive defences that are always present
69
what is the role of passive defences in plants?
to prevent entry and spread of a pathogen
70
what kind of defence do plants have when a plant detects a pathogen?
active defences
71
what are some physical defences that plants have?
-cellulose cell wall- barrier
-waxy cuticles
-lignin thickening of cell wall- waterproof
-stomatal closure
72
what are some chemical defences that plants have?
-terpenoid- antibacterial and antifungal
-phenol- antibacterial and antifungal
-alkaloid- nitrogen containing compound
-defensive proteins- small cysteine rich protein
73
what is a terpenoid?
antibacterial and antifungal essential oils
74
what is a phenol?
antibacterial and antifungal
75
what is an alkaloid?
nitrogen containing compound
caffeine, nicotine can inhibit enzyme action or protein synthesis
76
what is callose?
a large polysaccharide
deposited in the seive tubes which blocks them
forms a barrier
77
what is tylose?
formation of a balloon like swelling that fills the xylem vessels
prevents the spread of pathogens
78
what happens once the active defnece is activated?
-cell walls become thickened and strengthened with additional cellulose
-deposition of callose between the plant cell wall and cell membrane near the invading pathogen
79
what is necrosis?
deliberate cell suicide
a few cells sacrifice themselves to save the rest of the plant
80
81
How many lines of defence against pathogens do humans have?
Have two
82
What is the primary non specific defence like?
They are always present and are rapidly activated
Non specific
83
Is the specific immune system fast?
It is slower to respond than
84
What does the outer layer of skin contain?
Keratin
85
What is keratin?
A touch fibrous protein that’s in the outer layer of skin
86
What’s the pH on the skin surface like?
Slightly acidic
Due to fatty acids that are secreted
87
Why is the skin slightly acidic?
Fatty acids that are secreted
88
What does the skin harbour as a primary non specific defence?
The skin harbours healthy microorganisms that out compete pathogens for space on its surface
89
What is sebum?
Oily waxy substance that is produced by sebaceous glands
90
What’s the hydrochloric acid in stomach for in primary non specific defence?
Secreted by parietal cells in the stomach
Kills bacteria ingested with food
91
L
92
Where do mucous membranes line?
The gut
Respiratory system
Reproductive system
93
Primary non-specific defence
What is mucus made of?
Glycoprotein molecules
94
Primary non-specific defence
What does mucus get secreted by?
Epithelial cells interspersed with goblet cells that secrete mucus
95
Primary non-specific defence
What does mucus contain?
Lysozymes which destroy bacterial and fungal cell walls
Also contains phagocytes which remove pathogens
96
Primary non-specific defence
What does mucus lysozymes do?
Destroy bacterial and fungal cell walls
97
Primary non-specific defence
What are repulsive reflexes?
Sneezing, coughing
When pathogens irritate the lining of the airway.
Eject pathogens from the upper air way tract.
98
Primary non-specific defence
Info about lysozymes?
Tears, sweat, Urine, breast milk, mucus and blood
Secreted into body fluids
Antibacterial agent by breaking bacterial and fungal fell walls
99
Why is our normal intestinal flora so important to our health?
Outcompete pathogens thus preventing infection from taking hold.
Also assist with digestion and some vitamin production
100
Primary non-specific defence
What will platelets do when they come into contact with collagen?
Secrete several substances such as
-An enzyme that triggers a cascade of reactions that result in formation of a blood clot
-serotonin Thag makes smooth muscle vasoconstrict and reduce blood supply to that area
101
Primary non-specific defence
What’s the first stage of a wound healing?
A scab
102
How does blood clot?
-Platelets stick to the collagen fibres and form a plug
-platelets become activated and release clotting factors
-clotting factors turn prothrombin into thrombin
-this required calcium and vitamin K
-thrombin catalyses soluble fibrinogen into insoluble fibrin
-fibrin forms a fibrous mesh that traps RBCs and strengthens the platelet plug forming a clot
103
what do you call it when a phagocyte engulfs a pathogen?
phagosome
104
what do you call it when a phagosome fuses with a lysosome?
a phagolysosome
105
in a phagolysosome, what do lysosomes do?
the lysosome releases hydrolytic enzymes which digest and destroy the bacterium
106
describe lymph
-excess tissue fluid drains into the lymph vessels
-pathogens in tissue fluid can enter the lymph
-pathogens are transported along the lymph system to the ymph nodes
-activity of phagocytes causes swelling of lymph
107
what is bigger, a macrophage or a neutrophil?
a macrophage is bigger than a neutrophil
108
what element of blood is the largest and has a kidney shapes nucleus?
monocytes
109
what shape nucleus do monocytes have?
kdney shaped
110
which element of blood has a relatively large nucleus?
lymphocyte
111
what do you call a monocyte that has left the blood and enters tissues?
a macrophage
112
what type of nucleus does a neutrophil have?
a lobed nucleus
113
what is the specific immune response like?
can target a specific pathogen but it is slower
114
how do the immune memory cells in specific response help?
means that it is very quick to react to a second invasion
115
what are the 2 main types of specific immune response?
cell-mediated response
humoral
116
what is the cell mediated response in specific immune response?
highly specialised cells that target pathogens that have invaded cell or cells that have been changed in some way
117
what is the humoral response in specific immune response?
response that targets pathogens in bodyfluids using antibodies
118
what are antigens?
proteins - polysaccharide
found on the surface of all cells and pathogens
119
what are lymphocytes?
a type of white blood cell
(leukocyte) found in the blood and the lymph nodes
120
what can lymphocytes do?
recognise antigen molecules on the surface of pathogens
121
where do B lymphocytes mature?
they mature in the Bone marrow
122
where do T lymphocytes mature?
in the thymus gland
123
when can cell-mediated immunity occur?
it can occur due to virus, mutation, APC, or transplanted tissue
124
where do immature T lymphocytes oriiginate from?
they originate in the bone marrow
mature in the thymus gland
125
what do T lymphocytes gain?
specific cell surface receptors called T Cell Receptors
TCRs
126
what is special about TCRs?
each receptor is complementary to a different antigen
127
what do we also cal T lymphocytes?
T cells
128
what are the different types of T cells?
T helper cells
T killer cells
129
what do T cells do when they have not encountered their specific antigen?
the T cells remain inactive
130
describe the stages of cell mediated immune response
1. The macrophage destroys a pathogen by phagocytosis.
2. It displays antigens on its surface and is now an antigen-presenting cell (APC)
3. APC interacts with a SPECIFIC T-helper cell.
4. it releases a chemican substance called INTERLEUKIN-1 (a cytokine)
5. Interleukin-1 stimulates the T-helper cell to release another cytokine INTERLEUKIN-2
6. the interleukin-2 binds to an antigen-specific receptor on a T killer Cell
7. This activates T lymphocytes
8. The process of activating a T lymphocyte is called CLONAL selection
9. Tc cells detect the anigen on the surface of infected body cells and produce preforin which forms spores in the membrane allowing water and ions into the cell which causes lysis
10. T memory cells are formed and theyre ready to respond if they ever come into contact with the specific antigen again
131
what is clonal selection?
where specific B or T-helper lymphocytes are selected as they are complementary to the antigen
132
