DISEASE Flashcards
(51 cards)
1
Q
Pathogen definition.
A
- Microorganisms that cause disease.
2
Q
Pathogen examples.
A
- Virus, Bacteria, Protists, Fungi.
3
Q
Communicable disease definition.
A
- Disease that is transmitted from one host to another.
4
Q
Direct transmission.
A
- Contact of skin, bodily fluids, inoculation, ingestion.
5
Q
Indirect transmission.
A
- Air, food, water, inanimate objects, other organisms (vectors).
6
Q
Plant defences (Physical).
A
- Callose= Harder for pathogens to enter cells.
- Cellulose cell walls= Barrier against pathogens.
- Waxy cuticle= Barrier + stops water collecting on leaves.
7
Q
Plant defences (Chemical).
A
- Saponins= Destroy cell membranes of other pathogens.
- Insect toxins= Reduces insect feeding.
- Phytoalexins= Inhibit growth of fungi + pathogens.
8
Q
Ring rot.
A
- Plant disease, Bacteria, affects potatoes/ aubergines/ tomatoes, Damages fruits/ leaves/ tubers, control by sanitising equipment.
9
Q
TMV.
A
- Plant, virus, Tobacco plants, Black spots/ damages fruits and leaves/ stunted growth, Remove infected leaves, separate infected plants, sterilise equipment.
10
Q
Potato blight
A
- Plant, Protist, Potato, Brown spots and dead patches, chemical treatments, good ventilation and early harvest.
11
Q
Black sigatoka.
A
- Plant, Fungi, bananas, attacks leaves, fungicides.
12
Q
Tb.
A
- Animal, Bacteria, humans/ cows/ pigs/badgers/deer, coughing/ fever/ weight loss, Bacteria infects phagocytes in the lungs, antibiotics.
13
Q
Bacterial meningitis.
A
- Animal, Bacteria, humans, rash/ stiff neck/ fever, bacterial infection, antibiotics.
14
Q
HIV/ AIDS.
A
- Animals, Virus, humans, fevers/ tiredness/ headaches, bodily fluids/ sexual contact, antiretroviral therapy.
15
Q
Influenza.
A
- Animal, Virus, fever/ headache/ coughing, viral infection kills ciliated epithelial cells, vaccinations.
16
Q
Malaria.
A
- Animal, Protist, humans, fever/ headache/ nausea/ vomiting, vectors, medicines.
17
Q
Ring worm.
A
- Animal, fungi, humans, rash/ itchy skin/ hair loss, skin contact, anti fungi.
18
Q
Primary defences.
A
- Prevent entry of pathogens.
- Skin, mucous membranes, blood clotting and wound repair, expulsive refluxes, inflammation.
19
Q
Skin.
A
- Prevent entry of pathogens.
- Physical barrier.
- Oily substance (sebum) inhibits growth of pathogens.
- Healthy microbes live on the skin+ out compete pathogens.
- Salt is left behind after sweat + lowers pH- prevents microbes reproducing.
20
Q
Mucous membranes.
A
- Mucus contains phagocytes.
- Lines body tracs.
- Goblet cells secrete sticky mucus.
Traps microbes + contains lysosomes which destroy microbial cell walls.
21
Q
Blood clotting and wound repair.
A
- Platelet cells adhere to collagen in the skin or the wall of the damaged vessel.
- Triggers secretion of thromboplastin + serotonin.
22
Q
Expulsive refluxes.
A
- Coughs, sneezes removes mucus + trapped pathogens from airways..
- Vomit + diarrhoea removes pathogens from the gut.
23
Q
Inflammation.
A
- Increases blood flow to area (vasodilation of arterioles), increases neutrophils and phagocytes in area, more tissue fluid from increased blood flow, isolates pathogens.
24
Q
Phagocytosis.
A
- Phagocyte recognises antigens of a pathogen.
- Cytoplasm of phagocyte moves around pathogen + engulfs. Can be made easier by the presence of opsonin.
- Pathogen is contained in a phagosome (vessel containing pathogen) in cytoplasm of phagocyte.
-Lysosome fuses with the phagosome (phagolysosome) + lysosome enzyme breaks down pathogen. - Antigens from pathogen are presented at plasma membrane (Antigen presenting cell- APC).
-Phagocyte produces cytokines (cell-signalling molecule) which triggers other cells of immune system.
25
Opsonin.
- Before phagocytosis.
- Opsonin attaches to pathogen.
- Phagocyte has complimentary receptors which aid recognition of pathogen.
26
Cytokines.
- Produced by phagocytes that have engulfed a pathogen.
- Cell-signalling molecules.
- Inform other phagocytes that the body is under attack, stimulating them to travel to the site of infection or inflammation.
- Increase body temp + stimulate specific response.
27
Ways antibodies kill pathogens.
- Agglutination, neutralisation of toxins, preventing pathogens from binding to human cells.
28
Agglutination.
- Lots of pathogens engulfed at once.
- Phagocyte binds to constant region of antibody (agglutinin).
- Clump together.
29
Neutralisation of toxins.
- Antibody (antitoxin) has complementary shape to toxin + binds.
- Phagocyte binds to constant region of antibody.
- Lots of toxins engulfed at once
30
Antibodies prevent pathogens from binging to human cells.
- Surface receptors usually complementary to antigens on pathogen + virus can invade the cell.
- Antibodies attach to pathogen + antigen can't bind to receptors- virus can't enter.
31
Antibody definition.
- A protein produced in response to the presence of an antigen.
- Complementary shape to antigen.
- 4 polypeptide chains.
32
Antigen definition.
- A foreign molecule that triggers an immune response.
- Surface of pathogen.
- Specific shape.
33
Antibody variable region.
- Different in every antibody due to different amino acid sequence.
34
Antibody constant region.
- Same in all antibodies, allows binding to receptors on phagocytes.
35
Antibody hinge.
- Allows flexibility + to attach to more than one antigen.
36
Disulphide bridge.
- Holds polypeptide chains together.
37
Antigen binding site.
- Specific shape for each antibody.
- Complementary shape to antigen.
38
Specific immune system- Activation of T-lymphocytes.
- Each T lymphocyte has different receptors on their surface + complementary to antigens.
- Clonal selection = Specific T lymph binds to complementary antigens.
- Antigens can be presented by: Infected cells present on surface + macrophages (cut up pathogens to display more antigens).
- Clonal expansion = Complementary T lymph divided by mitosis + produces clones.
- Differentiation = Differentiates into: T helper/ killer/ memory/ regulatory.
39
T killer cells.
- Kill infected body cells.
40
T regulatory cells.
- Supress immune system and help prevent autoimmune response.
41
T helper cells.
- Release interleukins (type of cytokine) which stimulates activation of B lymph.
- Example of cell signalling.
42
T/ B memory cells.
- Stay in the blood.
- When infected with same pathogen, clonal expansion happen very quickly before you get ill.
43
Activation of B lymphocytes.
- Interleukins from T helper cells bind to receptors on membrane of the B lymph and activate it.
- Clonal selection.
- Clonal expansion.
- Differentiation.
44
B plasma cells.
- Produce antibodies.
45
B effector cells.
- Divide to perform plasma clone cells.
46
Types of immunity.
- Natural= pathogen enters naturally.
- Artificial= Vaccination, injection etc.
- Active= Body produces antibodies.
- Passive= Antibodies put into body.
47
Autoimmune disease.
- Organism sees own cells antigens as foreign and launches immune response against own tissues.
48
Type 1 diabetes.
- Affects pancreas.
- Thirsty, urinating, fatigue, weight loss.
- No treatment, insulin injections, transplant + immunosuppressants.
49
Rheumatoid arthritis.
- Hands, feet, wrists.
- Swollen, stiff + painful joints.
- Medication relieves symptoms and slows down progress, surgery, immunosuppressants.
50
Lupus.
- Skin, joints, organs.
- Fatigue, rashes, joint pain.
- No cure, Medications , immunosuppressants.
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