Specific Immune Responses Flashcards
What type of white blood cells make up the specific immune response?
Lymphocytes make up the specific immune response.
What are the positives and negatives of lymphocytes?
Lymphocytes can target a specific pathogen
But they are much slower to act than the non-specific response
What are the 2 main types of response that the specific response features to pathogens?
The humoral response
The cellular response
Define what is meant by humoral response?
The humoral response - this is the response that targets pathogens in body fluid with antibodies
The cellular response - this is the response which involves highly-specialised cells that target pathogens inside cells
What is cell signalling?
The specific immune response involves a coordinated response between a wide range of cells.
In order to work together effectively, these cells need to communicate.
This is known as cell signalling.
How is cell signalling achieved in cells?
Cell signalling - is achieved through cell surface molecules
And through the release of hormone-like chemicals called cytokines
What must the target cell have in order to detect a signal?
In order to detect a signal, the target cell must have a specific cell surface receptor that is complementary to the cell surface molecule or chemical.
What are the ways in which the specific immune response can be initiated?
1) The ‘Pathogen’ itself
2) infected body cells
3) antigen presentation
4) hormone-like chemicals
What does an invading pathogen have which act as a marker, which is then detected by our body cells and cells of the immune response?
An invading pathogen has foreign antigens. These foreign antigens act as flags or markers that say ‘I am foreign’ and therefore these can be detected by our body cells and cells of the immune response
How are infected body cells involved in initiating a specific immune response?
- infected body cells are involved in sending out ‘distress signals’
What does a body cell do once infected?
When a body cell is infected, the internal cell organelles such as lysosomes will attempt to fight the pathogen
As a result a number of pathogen cells can become damaged and parts can then often end up attached to the plasma membrane
What functions does the fact that some of the pathogen can end up attached to the plasma membrane have?
Pathogen parts attached to infected body cells can act as a distress signal and be detected by cells from the immune system
It can also act as a marker to indicate that the host cell is infected - T killer cells (a specialised WBC which will be explained later) can recognise this and can destroy it
Identify the type of phagocyte which take antigen-presentation to the next level?
Macrophages in the lymph nodes - play an important role in initiating the specific response to a disease
Explain how a macrophage becomes an antigen presenting cell?
- When a phagocyte engulfs a pathogen it incorporates part of the pathogen onto its cell surface
- It then becomes known as an antigen-presenting cell. An antigen-presenting cells is meant to activate the cells of the specific immune response that can ‘combat’ the pathogen more effectively
What is the name of the hormone-like chemicals that are released by cells which can act as instructions to many of the cells of the immune response?
Cytokines - act as instructions to many of the cells of the immune response
What are monokines?
Monokines - these are released by macrophages. Monokines are cytokines which attract nearby neutrophils by chemotaxis
What is chemotaxis?
Attraction by chemicals
What are interleukins?
These are released by macrophages
These are cytokines which can stimulate the proliferations and differentiations of the specific immune system such as B and T cells
What is proliferation?
Dividing of cells to increase numbers
Define lymphocytes:
Lymphocytes are relatively small WBC
They circulate around the body in the BLOOD and the LYMPH
They are the WBC involved in the specific immune response
Name the two main types of lymphocytes?
- T-lymphocyte
2. B-lymphocyte
Where are T-lymphocytes and B-lymphocytes produced?
Bone marrow
Where do T-lymphocytes mature?
THYMUS
Where do B-lymphocytes mature?
BONE MARROW
Once both types of lymphocytes are mature they reside in various locations in the body, but especially which location?
Especially high numbers can be observed within the lymph nodes
What do lymphocytes produce as they mature?
As they mature lymphocytes produce small quantities of a particular glycoprotein called antibodies.
When antibodies are placed onto the plasma membrane of lymphocytes what do they act as?
The antibodies act as receptor which are able to bind with a particular antigen, if this should appear in the body.
What happens if pathogens do enter the body and the lymphocytes have receptor that are complementary to the antigen on the pathogen?
Then a response is triggered and B-lymphocytes and T-lymphocyte respond in different ways.
What type of lymphocytes are involved in the cell mediated response?
T-LYMPHOCYTE are involved in the cell-mediated response because they do not involve antibodies but target and story cells that are directly infected by pathogens.
What is the first step that initiates the T-lymphocyte?
Stp 1:
An antigen-presenting cell macrophage, ingests, processes and presents the antigen on its cell surface membrane
This is known as antigen-presentations