Disease And The Immune System Flashcards
1
Q
Name three communicable diseases caused by virus
A
- HIV/AIDS (human)
- Influenza (animals)
- Tobacco mosaic viruses (plants)
2
Q
Name three comunicable diseases caused by bacteria
A
- Ring rot (potatoes and tomatoes)
- Tuberculosis (animals)
- Bacterial meningitis (human)
3
Q
Name three communicable diseases caused by fungi
A
- Ring worm (cattle)
- Athletes foot (human)
- Black Sigatoka (banana)
4
Q
Name two communicable diseases caused by protoctists
A
- Malaria
- Potato and tomato blight
5
Q
Different types of Direct transmission in animals
A
- Direct contact: skin to skin contact or contact with bodily fluids
- Inoculation: through a break in the skin
- Ingestion: taking in contaminated food or drink, or transferring pathogens mouth to hand
6
Q
Different types of Indirect transmission in animals
A
- Fomites: inanimate objects such as bedding, socks or cosmetics can transfer pathogens
- Droplet infection: minute droplets of saliva and mucus are expelled form you mouth as you talk, cough or sneeze. These droplets can contain pathogens
- Vectors: a vector transmits communicable pathogens from one host to another
7
Q
Factors that affect the transmission communicable disease in animals
A
- Overcrowded living and work conditions
- Poor nutrition
- A compromised immune system
- Poor disposal of waste, creates a breeding site for pathogens
- Climate change, introduces new vectors and diseases
- Culture and infrastructure, traditional medical practices increase transmission
- socioeconomic factors, a lack of trained health of public warning that there is an outbreak
8
Q
How are pathogens Directly transmitted in plants
A
-Involves direct contact of a healthy plant with any part of s diseased plant
9
Q
Types of indirect transmission in plants
A
- Vectors: humans, water, animals and humans
- Infected plants leave pathogens or reproductive spores from protoctists or fungi in the soil. These can infect the next crop.
10
Q
Factores effecting the transmission of communicable disease in plants
A
- Planting varieties, planting crops that are susceptible to disease
- Overcrowding increases likelihood of contact
- Poor mineral nutrition reduces resistance of plants
- Damp warm conditions increases the survival and spread of pathogens and spores
- climate change, increase rainfall and wind promote spread of disease
11
Q
What are the plants physical active defence of disease
A
-Callose is synthesised and deposited between the cell walls and cell membrane in cells next to the infected cell. They act as barriers that prevent the pathogen from entering.
12
Q
What are some passive physical defence of the plant
A
- They have a waxy cuticle which provides a physical barrier against pathogen entry. Also stops water accumulating on the leaf.
- Plants have cell wall which act as a barrier if they make it past the waxy cuticle.
13
Q
What are chemical defences in plants
A
- Insect repellant
- Insecticides
- Antibacterial compounds
- Anti fungal compounds
- Anti oomycetes
- General toxins
14
Q
How do plants recognised they are being attacked
A
Receptors in the cell respond to molecules from the pathogen or from chemicals produced when the cell wall is attacked. This triggers cell signalling that switch on genes. This in turn triggers a cellular response.
15
Q
What is the innate non-specific primary defence
A
Keeping pathogens out of the body
16
Q
What is the innate non-specific secondary defence
A
Is getting rid of pathogens in the body
17
Q
What is the adaptive specific immune response
A
Is specifically targeting pathogens; this is immunity
18
Q
Examples of innate non specific primary defence
A
- Mucous membranes: they secrete mucus which traps microorganisms, the mucus has lysozyme which destroys the bacteria cell walls. This protects body openings such as nostrils.
- Skin a physical barrier
- Blood coagulation, when blood clots to plug wounds and prevent pathogens entering
- Inflammatory response
19
Q
What is the inflammatory response
A
- Mast cells release histamine sand cytokines
- Histamines cause vasodilation which causes localised heat which prevents pathogens reproducing
- Histamines increase capillary wall permeability so plasma is forced out
- cytokines attract phagocytes to that location.
20
Q
Stages of phagocytosis
A
- Pathogens produce chemicals that attract pathogens
- Phagocytes recognise foreign antigens on the pathogen.
- The phagocytes engulf the pathogen and encloses it in a vacuole called a phagosome
- The phagosome combines with a lysosomes to form a phagolysome
- Enzymes from the lysosomes digest and destroy the pathogen
- The phagocyte if a macrophage then presents the antigen becoming an antigen presenting cell
21
Q
What do cytokines do
A
They act as cell signalling molecules attracting phagocytes.
22
Q
What do opsonins do
A
They are chemicals that bind to pathogens and tag them so they can be more easily recognised by phagocytes. Phagocytes have receptors that bind to common opsonins, so it can engulf it.
23
Q
What is the immune response
A
The action of lymphocytes in response to a non self antigen entering the body
24
Q
What are the 2 types of lymphocytes
A
B lymphocytes and T lymphocytes
25
What are the different types of T lymphocytes and where do they mature
T lymphocytes nature in the thymus and produce T killers, T helpers, T memory and T regulators
26
Where is B lymphocytes produced, stored and what are the different types
B lymphocytes are stored in lymph nodes and are made in bone marrow.
There are B plasma cells and B memory cells
27
What do t helper cells do
They produce interleukins when they bind to an APC. Interleukins stimulate activity of B cells and cause it to divide
28
What do t killer cells do
They kill infected cells
29
What do t regulatory cells do
They suppress your immune system so that white blood cells don't attack the hosts body cells
30
What do t memory cells do
They divide rapidly to form large amounts of T cells if they encounter the antigen for a second time
31
What do B plasma cells do
They produce antibodies for a specific antigen and release them into circulation
32
What do B memory cells do
They divide rapidly in plasma cells to produce antibodies if they encounter the same antigen for a second time.
33
What is clonal expansion
Is when the T or B lymphocytes divides to produce clones of itself by mitosis
34
What is clonal selection
When a B or T lymphocyte receptor binds to a specific antigen
35
What is cell mediated immunity
- When macrophages engulf pathogens they display its antigens, becoming an APC.
- T helper cells then bind to the APC however they have to be complementary. This is clonal selection.
- T helper cells then become activated and produce interleukins which stimulates more T helper cells to divide rapidly by mitosis. This is clonal expansion.
- T helper cells produce interleukins which stimulate activity of B cells and stimulate of production of other T cells.
- T cells then differentiate
36
What is humoral immunity
- B lymphocytes have antibodies on their cell surface membrane and when they bind to a complementary antigen, it engulfs and processes the antigens to become an APC.
- Activated T helper cells then bind to the B lymphocytes ( clonal selection) and produces interleukins which activates the B cell.
- The activated B cells divide by mitosis. This is clonal expansion.
- The cloned B cells then differentiate into B plasma cells and B memory cells.
37
What are neutrophils
They are a type of phagocyte and are the first white blood cell to respond to a pathogen inside the body.
38
What is the purpose of the hinge in antibodies
Allows the molecule to bind to two separate antigens one at each binding site by providing flexibility
39
What is the variable region on antibodies
It is the antigen binding site, this area is specific for a specific antigen so it can vary shape. Antibodies bind to antigens by the lock and key mechanism forming an antigen-antibody complex.
40
What bonds join the heavy peptide chain to the light peptide chain
Disulphide bonds/bridges
41
How do antibodies defend the body
- The antibody of the antigen-antibody complex acts as an opsonins so the complex is easily engulfed and digested by phagocytes
- Most pathogens can no longer effectively invade the host cell once they are apart of the antigen-antibody complex.
- Antibodies acts as agglutinins causing pathogen carrying antigen-antibody complexes to clump together so they can be engulfed in one go.
- Antibodies act as antitoxins, binding to the toxins produced by pathogens making them harmless
42
What is an Autoimmune disease
It is when the immune system stops recognising self antigens and starts to attack the hosts healthy body tissue. This is a genetic tendency where T regulators don't work effectively.
43
Examples of autoimmune diseases
- lupus
- arthritis
- type 1 diabetes
44
What is the primary immune response
When a pathogens enters the body for the first time it's responde is slower because there aren't many B lymphocytes. After being exposed to the antigen T and B lymphocytes produce memory cells.
45
What is the second immune response
If the same pathogen enters the body again, the immune response will produce a quicker stronger immune response, due to the memory cells.
46
What is artificial immunity
It is when the body is given immunity temporarily or permanently
47
What is natural immunity
It is when you gain temporary or permanent immunity naturally without any artificial influences
48
What is passive immunity
When antibodies are given to you. This can be by an injection form from your mother when you are a baby via the placenta.
49
What is active immunity
It is when your body makes its own antibodies this can be a result of a vaccination or an infection
50
What types of forms are antigenic material present in
- Killed or inactive bacteria or virus
- Attenuated (weakened) strains of live bacteria or viruses
- Toxin molecules that have been altered and detoxified
- Isolated antigens extracted from pathogens
- Genetically engineered antigens
51
What is an epidemic
When a communicable disease spreads rapidly to a lot of people on a local or national level
52
What is a pandemic
It is when a communicable disease spreads rapidly across a number of countries and continentes
53
How does herd immunisation control an epidemic
-At the beginning of an epidemic mass vaccinations can prevent the spread of pathogens. When a significant number of the population have been vaccinated this gives protection to those who do not have immunity. This is known as herd immunity as there is minimal opportunity for an outbreak to occur.
54
Define the term parasite
On organisms that benefits off another by living on the hist and gaining nutrients, while the host suffers
55
What is the function of the constant region in antibodies
It allows the phagocyte to bind to the pathogen
56
Outline the process of neutralisation
Antibodies produce antitoxins that bind to toxins and prevent the toxins affecting the host cell
57
Outline the process of agglutination
Group of pathogens clump together so they can be engulfed by phagocytes in one go
58
Why do we need to develop new drugs
- New disease are emerging and others changing
- Some diseases have no effective treatment
- Antibiotic treatments are losing their effectiveness
59
Where have our current medicines come from
```
Accidental discovery
Tradition remedies
Observation of wildlife
Pharmacogenetics
Synthetic biology
```
60
What is pharmacogenetics
- Studying the make up of an individual genetically in relation to drug interactions
- Analysing the genome of both patient and pathogen to determine treatment
61
What is synthetic biology
- developing new molecules that mimics biological systems
- culturing bacteria to act as biological factories that produce more expensive drugs
- delivery of therapeutic molecules using nano particles
62
Why do viruses do not use erythrocytes as host cells
Because they have no nucleus, no DNA and ribosomes which they need for proteins synthesis
63
Why does plasmodium spends part of its life cycles in erythrocytes
They use the host cell to hides its self from the immune system.
