4.1 Communicable diseases Flashcards
What is clonal selection?
Selection of a specific B or T cell that is specific to the antigen.
What is a neutrophil?
A type of white blood cell that engulfs foreign matter and traps in a large vacuole called a phagosome.
What are opsonins?
Antibodies that bind to the antigen on a pathogen and then allow phagocytes to bind.
What are secondary defences?
Defences used to combat pathogens that have entered the body.
What are phagocytes?
The first line of secondary defence is phagocytosis where the phagocytes engulf and digest the pathogens.
What are macrophages?
similar to phagocytes, except they don’t fully digest the pathogen as it moves an antigen from the surface of the pathogen and attaches it to its own special protein complex, so other immune response cells can recognise the antigen.
How do antigen presenting cells help the lymphocytes?
As there may be only one Tand one B cell which is specific to the pathogen, so the chances of meeting the pathogen are small.
Therefore these antigen presenting cells may increase the chances the antigen will come in contact with them
What do T helper cells do?
T helper cells release cytokines that activate specific T and B lymphocytes which would be made complimentary to the pathogens antigens.
What are the four types of T lymphocytes?
- T helper cells
- T killer cells
- T memory cells
- T regulator cells
What do T killer cells do?
Attack and kill cells which display foreign antigens
What do T memory cells?
Provide long term immunity, as they circulate around in the blood
What are T regulator cells?
They shut down the immune respone after the pathogen has been successfully removed. They are also involved in preventing autoimmunity
What are the different types of B lymphocytes?
- plasma cells
- b memory cells
What is the difference between plasma cells and b memory cells?
Plasma cells circulate in the blood releasing antibodies.
B memory cells remain in the body for years and help for a quicker immune response second time round.
What do monokines do?
Monokines is a chemical released by macrophages that either:
-Attract or neutrophils
or
-stimulate b cells to differentiate and release anybodies.
What are antibodies?
Special proteins that attach to antigens, rendering them harmless allowing a phagocyte to attach and ingest the phagocyte.
What is the name of the region on an antibody which is specific to the shape of the antigen?
The Variable region
What is the name of the region on an antibody which allows binding to our own phagocytes cells and is the same in every antibody?
Constant region
What is the hinge region?
The region in the middle of the antibody which allows flexibility for movement, and it to bind to more than one molecule at once
What is the role of disulfide bridge in an anti body?
Hold the polypeptides together.
What is agglutination?
When antibodies clump together with other pathogens which:
- stops them from passing through host cell membranes
- makes them easier to be engulfed.
What are anti-toxins?
Antibodies that bind to toxins released by pathogenic cells, rendering them harmless.
What are protista?
Eukaryotic cells which can act as pathogens and infect cells such as the malaria protista.
What are the stages of specific immune response?
1) The foreign antigen is detected
2) Phagocytosis occurs
3) Antigen-presenting cells present antigen
4) Correct T and B cells are selected
5) Correct t cells undergo clonal expansion through mitosis
6) T-helper cells release cytokines that stimulate b-cells to differentiate neutrophils
7) reproduction of B cells
What are the functions of antibodies?
- Agglutinating pathogens (clumping together of pathogens and antibodies)
- neutralising toxins
- neutralising pathogens
- opsonisation (allow phagocytic cells to bind more easily and destroy the pathogens)
How do vaccinations work?
A weakened version of the pathogen is injected, which triggers immune response and memory lymphocytes to be made.
What is herd vaccination?
When a vaccine is used to provide immunity to all or almost all of the population at risk. Once enough people are immune the disease can no longer be spread.
What is ring vaccination?
When a new case of a disease is reported and all the people in the immediate vicinity of the disease are vaccinated. This is also often used for controlling diseases affecting live stock.
What are the different types of immunity?
natural or artificial immunity
and
passive or active immunity
What is the difference between natural and artificial immunity?
Natural immunity is achieved through normal life process such as catching chicken pox.
Artificial is achieved through medical intervention.
What is the difference between active and passive immunity?
Active immunity is when the immune system is activated and manufactures its own antibodies.
Passive immunity is when antibodies are supplied from another source such as during pregnancy through the placenta or by injection of antibodies.
What is the wave hub regeneration project?
A wave power research project.
Costs
- 42 million to build
- potential disturbance of that area of the Cornish coast for marine life
Benefits
- Earn £76 million in the next 25 years for the Cornish economy
- create 170 jobs - reducing the brain drain
What was the benefits and costs of the superfast broadband regeneration project in Cornwall?
Costs -£132 million Benefits -encourages businesses to set up -aids the knowledge economy and those who work from home -hence reducing the brain drain -economic impact of £200 million
Where are t-cells matured?
Thymus
Where are b-cells matured?
Bone marrow
Which cells release antibodies?
B cells
plasma and memory cells
How can you recognise a neutrophil from other phagocytes?
They have a multi-lobed nucleus.
Why do other cells of the immune system not attack macrophages when they become an antigen-presenting cell?
Because the antigen is displayed on a special protein complex.
